It’s the age-old chicken-or-egg story of the housing market: Should you buy that home now, while interest rates are still fairly low? Or wait for rising prices to moderate?

Of course, there are many factors that will go into your decision. But here’s one you probably haven’t considered, and it has real “buy now” implications: Mortgage payments zoomed last year and are likely to rise even higher this year, continuing a trend that has persisted for the past six years.

CoreLogic, a data analytics company that has been tracking mortgage payments for the past generation, says that while home prices may be up 6 percent through August of last year, the average mortgage payment went up 10.1 percent during the corresponding period. And for 2018, the typical home loan payment is likely to rise by more than 11 percent.

That’s a good bit more than most of us have been seeing in yearly raises, if we get them at all.

CoreLogic’s “typical mortgage payment” (TMP) is a mortgage rate-adjusted monthly payment based on each month’s median home sale price in the United States. It tends to move up or down based on factors such as mortgage rates and size of down payments.

Their TMP can help buyers judge affordability, according to CoreLogic’s Andrew LePage, “because it shows the monthly amount a borrower would have to qualify for in order to get a mortgage to buy the median priced home.”

Of the four components of a mortgage payment -- often compartmentalized as PITI, for principal, interest, taxes and insurance -- the TMP measures only the principal and interest payments. It assumes a 20 percent down payment, the amount necessary to avoid having to pay for private mortgage insurance (PMI), and a 30-year, fixed-rate loan. Of course, many homebuyers put less than 20 percent down and must purchase PMI, which can add several hundred dollars more to their monthly house payment.

The typical mortgage payment was higher than today’s TMP before the Great Recession, which stands to reason, as home prices climbed to unsustainable highs before the markets crashed in 2008. Back in June 2006, before things started to go south, the typical monthly payment was $1,250. That fell to a low of $546 in February 2012, and has risen steadily since then to $816 as of August of last year. That comes to about a 50 percent increase over five years, or about 10 percent a year.

Of course, in 2006, the average mortgage rate was a lot higher: 6.7 percent, compared to 3.9 percent last August. And the inflation-adjusted median sales price was higher, too: $243,000, compared with $217,000 last year.

In addition to last year’s 10 percent jump in the TMP, CoreLogic is predicting that the typical payment is projected to rise by 11.3 percent this year, to $908.

“Real disposable income is projected to rise 3.6 percent over the same period, meaning this year’s buyers would see a larger chunk of their incomes devoted to mortgage payments,” says LePage.

That makes for a good argument to buy that home now. But there’s an inventory problem, with many potential sellers on the fence about whether to sell or not.

According to down payment protection firm ValueInsured, sellers are hesitating to sell now because of the high price they feel they will have to pay for their next homes. The firm conducted a survey of about 1,000 American homeowners, and many of those who say they want to sell -- either to upgrade or downsize -- are having second thoughts.

“Homeowners, in many cases, are eager to sell but don’t want to become buyers,” says Joe Melendez, chief executive of ValueInsured.

So even though it’s a seller’s market due to low inventory, some owners are thinking of renting their houses rather than selling. Either that, or they are considering passing their homes on to a family member. Even millennials are taking a wait-and-see attitude because of uncertainty over job changes.

Here’s what the numbers look like, according to the ValueInsured survey:

-- 72 percent say they are concerned with timing the real estate market.

-- 63 percent say now is a good time for them to sell, but not to buy, due to high home prices.

-- 61 percent are “waiting until prices to buy are better to make a move.”

About 26 percent of potential sellers “say they second-guess their desire to sell because they don’t want to pay brokers’ fees, new mortgage closing costs, capital gains taxes and other associated expenses, as it would weaken their buying power for their next home,” says the firm.

There’s no doubt that many housing markets are currently overvalued: According to a recent CoreLogic report, 48 of the nation’s top 50 markets are overvalued.

According to Melendez, “These homeowners have experienced a lot of home-value volatility and see more uncertainties looming -- tax reform, for example. By hesitating, these homeowners are actually controlling the market on both sides. Reassuring these individuals is the key to unlocking inventory.”

He adds, “selling and buying are always fraught with worrying about timing the market, and life events don’t always cooperate.”

Taking the longer view may be helpful for both would-be buyers and sellers, he says. “Eventually, younger people move for jobs and empty-nesters need to leave their five-bedroom homes.”

-- Freelance writer Mark Fogarty contributed to this report.

When there is a dispute between buyer and seller over what stays with the house and what goes, it’s usually over a prized bathroom mirror, a beautiful sconce in the hallway or some ornate, custom curtain rods.

The rule of conveyances is fairly simple: If it is attached to the house, it is considered a fixture and it stays for the next owner. If it isn’t attached, the sellers can take it with them when they move out. In other words, you can take the curtains, but not the rods.

But what if the issue involves animals? Now it gets sticky. Obviously, the dog or cat or other critter isn’t part of the property, and normally the sellers will take their pets when they leave. But not always.

Last fall, agent Jeff Dowler of Solutions Real Estate in Carlsbad, California, asked a seller if the peacocks wandering around his spacious backyard would be part of the transaction.

“The lot was large, about one acre, and the seller met us at the property to let us in,” Dowler said in a post on real estate site ActiveRain. “The buyers were out strolling the property, and out of curiosity, I asked, ‘Do the peacocks convey?’”

The seller was adamant: “Yes, they are staying,” he said.

As it turns out, peacocks are protected in several parts of the country, allowed to roam freely. So they had to stay, whether the buyer liked it or not.

Francine Viola, an agent with Evergreen Olympic Realty in Washington, once had to write up a contract that stated the chickens in the coop would stay. If that wasn’t enough, the buyer also wanted the seller to replace any chickens that passed away prior to closing.

“Thankfully the chickens lived,” she said.

Ducks were part of a deal that New Hampshire agent Scott Godzyk once worked on. The buyer wanted the ducks in the property’s small pond to convey. Luckily, the sellers agreed. It seemed the husband, who fed them daily, didn’t want them to be disturbed from their man-made habitat.

Fish or fowl, there can be problems. Twice, Dana Cottingame of Coldwell Banker in Dallas ran into situations with koi in a pond. In Texas, she learned, koi convey just as though they were attached to the house. The moral here: If you don’t want to be bothered feeding fish, don’t buy a house with them -- at least in the Lone Star State.

In Florida, Winifred Smith of RE/MAX Advance Realty says she heard of an issue with the number of koi that would convey with a certain home. The larger koi are apparently “quite expensive, so the buyer made the seller pay to replace a couple” that had gone to the great pond in the sky.

Things don’t always work out when a pet is involved. One odd request reported by Goodson Realty in Bonne Terre, Missouri, came from a buyer who fell in love with the seller’s dog and wrote him into the contract. “My sellers did not accept” the offer, recalls the agent.

And sometimes the problem is big -- really big, as in the case of the three 400-lb. potbellied pigs that greeted Anna Kruchten of the Phoenix Property Shoppe when showing her client an upscale luxury home. The listing agent hadn’t mentioned a thing about the porkers, even when Krutchen spoke with him directly.

The seller’s agent probably thought the presence of pigs was better left unsaid. Otherwise, nobody would want to visit the place. And as you might expect, Kruchten says, “my client was aghast.”

Neither Gayle Rich-Boxman of Fishhawk Lake Real Estate in Birkenfeld, Oregon, or RE/MAX agents Pat and Ed Okenica in Lake Oconee, Georgia, have had any problems with live animals. But they have had issues with taxidermy and telephones.

Rich-Boxman had to remove a moose head on New Year’s Day a few years back, because the sellers thought it was a fixture and left it -- “and weren’t coming back” for it. The buyers didn’t want the “sad old head leering at them,” she recalls, so she hired workers to remove it.

The Okenicas, meanwhile, had buyers who insisted the sellers leave their phone, shaped like a mallard duck, or they would walk away from the deal. “There’s always something that pops up in a transaction that you least expect,” they posted.

Adjustable-rate mortgages (ARMs) are back, especially in the higher price brackets around $453,000 and above. And as loan rates climb, as they are expected to do throughout the year, they probably will become more popular.

But wait: Weren’t ARMs responsible, at least in part, for the 2008 housing crash and subsequent mortgage market meltdown? Are homebuyers setting themselves up for another fall?

Well, no, ARMs weren’t responsible for the crash. Actually, the loan product itself is quite sound. After a set number of years, the rate you pay adjusts to market conditions at that time. The rate could go up -- by as much as 2 percentage points a year, usually, to a maximum of 6 points over the life of the loan -- or it could go down.

No, what got borrowers and lenders into trouble wasn’t ARM loans; it was the loose standards underwriting them. At the time, the joke was that if you could fog a mirror, you qualified for a mortgage.

The dicey variations of ARMs, though, were no joke. These included loans in which only interest was collected for a set period; “pay option” ARMs, in which you decided when to pay and how much; and negative amortization ARMs, in which the loan balance actually went up, not down. Some lenders approved these and other loans with little or no documentation to prove borrowers were employed, or that they earned enough to make their payments.

“The underwriting standards used to approve borrowers for those loans by some lenders were abysmal,” says Quicken Loans Chief Economist Bob Walters.

Today’s ARMs, however, are “very different” from the pre-crash versions, according to Archana Pradhan, an economist for analytics firm CoreLogic. According to CoreLogic, 3 out of every 5 ARMs originated in 2007 were either low- or no-documentation loans. In 2005, 3 out of 10 ARM borrowers had credit scores below 640.

Today, says Pradhan, almost all adjustable loans are full-documentation, fully amortizing loans made to borrowers with credit scores above 640. Also pretty much gone are the so-called teaser rates -- rates that started as much as 3 percentage points below the true starting rate -- that were offered to entice borrowers.

Based on the four major underwriting variables -- credit score, loan-to-value ratio, debt-to-income ratio and documentation -- ARMs are of “better quality” than even fixed-rate loans, Pradhan reports. As of last year’s first quarter, for example, the average credit score among ARM borrowers was 765, versus 753 for those taking out fixed-rate loans. And the typical LTV was 67 percent on adjustables, versus 74 percent for fixed loans.

But the real proof of how well these loans are underwritten now is that they are performing admirably. While their borrowers still become seriously delinquent more often than fixed rate borrowers, according to CoreLogic’s figures, the rate at which ARMs become major problem loans is significantly lower than they used to. And the bulk of today’s super-late loans -- those that are 90 or more days overdue -- were originated between 2003 and 2009.

No wonder, then, that borrowers are heeding the new call to ARMs. (Sorry, I just had to.)

Uncle Sam no longer counts the number of adjustable loans and fixed mortgages, but several private sources show how great a comeback ARMs have made recently.

According to the Inside Mortgage Finance trade publication, ARM originations leaped 40.5 percent in last year’s second quarter. And Black Knight, another mortgage information and analytics firm, says that ARMs now represent 9.5 percent of all active loans.

However, the story with ARMs today is a tale of two markets: one below the conforming loan limit of $453,000, and the other above it. The conforming limit is the ceiling placed on the size of the loans Fannie Mae and Freddie Mac can purchase from lenders on the secondary market. Anything above that is considered a “jumbo” loan.

According to the Mortgage Bankers Association, as of October, just 3.2 percent of all conforming loans were ARMs. On the flip side, the ARM share of jumbo loans was over 35 percent (as of December 2013). And more recently, jumbo ARMs have consistently been responsible for a 20- to 25-percent share of the entire mortgage market.

This makes perfect sense to MBA economist Joel Kan, who says higher-end borrowers have the income and credit necessary to “absorb the interest rate risk” that comes with adjustable rate mortgages.

Of course, ARMs are not for everyone. Far from it. “There is never a one-size-fits-all” loan product, says Quicken’s Walters, who uses an ARM on his own residence. “But they are not the villains they are sometimes portrayed to be.”

Because ARMs come with lower starting rates than fixed-rate loans, the ideal candidate is someone who can peg a major life event to the first adjustment period. For example, if you expect to upgrade or downsize within a certain timeframe, or you don’t plan to be in the house you’re buying very long, you should take a serious look at that option.