Everything is negotiable in real estate -- even when it comes to renting a place to live.

Most people don't realize that landlords are sometimes willing to bargain. That's particularly true of Mom and Pop property owners who have only one or two houses to rent. But even property managers at huge apartment complexes and skyscraper high-rises can be talked into cutting the rent a bit.

No one keeps statistics on how many renters actually go back and forth with their landlords about how much they'll have to pay every month. Nor does anyone know how much people usually save. But the folks at apartmentlist.com, a national apartment search engine, say that negotiating a savings of $200 a month -- that's $2,400 a year! -- isn't unheard of.

It's not always about money, though, at least not directly. And especially at a large complex where rents are set it stone.

Perhaps you can bargain for a free parking space, or place for your boat or RV. Or maybe the landlord might be willing to throw in free storage. How about asking the landlord to paint your unit, upgrade your appliances or pay for a gym membership, if your building is without such facilities? Remember, everything is negotiable, even the length of your lease.

If you think negotiating your rent is underhanded or even sordid, think again. "Negotiation on rent, or anything else in life, doesn't have to be sleazy if you handle it like a decent human being," says ApartmentList. "It's simply a conversation to work out a newly improved situation for both rent and landlord, and there's nothing to feel bad about."

Timing, of course, is everything. And the best time to ask your landlord to trim the rent is when you're about to extend your lease for another year. When you know you want to stay, your landlord might be willing to cut you a deal if he doesn't have to repaint the place, clean it up and look for another tenant.

It's expensive to find new tenants; the possibility of lost revenue, should the landlord not find someone to replace you right away, can be a powerful bargaining point on your side of the table.

Most leases require that tenants give their landlords at least 30 days written notice when they plan to leave. But if your lease has no such clause, a good time to try to strike a deal is just before the end of the month. This places added pressure on landlords, because the chances of finding another tenant quickly enough to not miss a month's rent are slim.

The dead of winter is also a good time to bargain. "This is the most difficult season for landlords to find renters, and you'll hold more bargaining power," says Andrew Woo, director of data science at the apartment site.

Woo suggests that before you sit down with your landlord, do some research. Find out what similar properties in the vicinity are renting for and what amenities they offer.

Another ploy: If you have the cash, offer to pay an entire year's rent in advance in exchange for a lower rent. Or maybe your landlord will be willing to cut you a deal if you pay just a few months' rent ahead of time.

Another possible bartering point is to offer to help out around the property. Maybe you can work in the office one day a week, or, if you have a particular trade, help the maintenance man. The idea here is to use whatever you have to trade for a better deal.

You also might be able to save a few bucks by offering to move to a less desirable unit, say one next to the trash dumpster, the noisy elevator or lobby, or even a smaller room or apartment that's difficult to lease. Every property has at least one unit that is a red herring.

Also, consider working with the landlord so that your new lease ends in the summer -- maybe signing a six-month or even an 18-month contract. Summer, ApartmentList points out, is when school's out, the weather's better and schedules are more flexible -- giving your landlord an easier time filling your unit after you do vacate.

When you have a good idea of what you want and may be willing to give up to get it, ask your landlord for a face-to-face meeting. Don't try to do this by email. Have your resources with you, including prices from other places, and your rental record that shows you always pay on time, if not early.

Finally, present your argument in a way that shows how it benefits your landlord as well as you.

"If you can pinpoint exactly how a new situation will be beneficial to both of you," says Woo, "it lessens any possible tension and is more likely to be successful."

Two online platforms that allow investors to sell occupied rented single-family homes without disturbing their tenants -- and buy rented houses with tenants already in place -- are among a plethora of new real-estate-centric sites that promise to improve the buying and selling process.

One, started by the co-founder of Uber, allows would-be buyers to see exactly what they're up against when competing with other potential buyers. Another allows real estate agents to compete for your listing, just like banks sometimes compete online through various portals for home loans.

The investor platforms -- Roofstock and OwnAmerica -- fill a real void.

Typically, when an investor wants to sell a house that he's held for awhile, he has to wait for the current tenants to leave when their lease expires or ask them to leave early. If he tries to put the house on the market while it is still occupied, it not only disturbs the occupants, it also puts them on notice that the house is up for grabs and often scares them into moving out.

Worse, though, is the possibility of lost income if the house lingers on the market for several months once it becomes empty and is listed for sale.

Both Roofstock and OwnAmerica are platforms that address these issues by quietly marketing investor-owned properties to other investors who are searching for properties that already are occupied, saving them the time and cost of finding tenants once the house changes hands.

"You'd never vacate an apartment building to sell it," says Roofstock co-founder Gary Beasley. "Why should rental homes be any different?"

This is hardly a niche market. It's roughly a $2 trillion business with some 15 million single-family rental houses nationwide.

About 13 percent of the U.S. population live in single-family rentals, yet no one really services them, at least not properly, Beasley and OwnAmerica CEO Gregory Rand contend. Existing channels specialize in selling vacant or soon-to-be vacant houses to owner-occupants, they say, but they are not well-equipped to sell with tenants in place.

While the two sites have the same mission, they work somewhat differently. With OwnAmerica, someone wanting to purchase an occupied rental property makes an offer without ever seeing it so the tenants are not agitated. Only when the contract is accepted can they actually visit and inspect the house. And if the property is not what was described online, or if it needs work, the buyer and seller can renegotiate.

At Roofstock, third-party experts inspect and certify houses as part of the listing process. Consequently, buyers have access to fully vetted properties with current cash flow and professional property management in place, and sellers can sell more quickly without losing much, if any, rent.

What's more, prices of houses listed on Roofstock are set in stone, based both on market comparables and property-specific conditions, so there's no back-and-forth haggling.

Another new site, Haus, is described as "an open and fair platform" that gives buyers and their agents access to all offers in front of a seller. So, if four other people make on offer an the house you've also bid on, you'll know exactly what the competition is proposing and, if you like, you can one-up them.

Currently, you may know others have submitted an offer, but the terms of those offers are confidential, so you have no idea what you are up against. Some buyers offer escalation clauses to best their competitors' best offer by, say, $1,000 and perhaps up to a certain amount.

But your rival bidders may also offer other goodies you don't know about -- giving up a home inspection, for example, or allowing the seller to remain in the house for a few extra months -- that could sway the seller.

Haus' goal is complete objectivity. It notifies agents, buyers and sellers when a new offer is submitted, and allows all of them to view the price and terms of all offers on the table at any given point in the transaction. Names are confidential, but everything else is revealed.

That way, both buyers and sellers can monitor listings, and all buyers can have a fair chance of seeing their bid accepted because they can see exactly where their offers stand vis-a-vis any others.

"Haus is creating a platform we believe can revolutionize the way people buy real estate," said Garrent Camp, an Uber co-founder and head of the startup studio that developed the program. "The open and clear communication creates a more efficient and fair process for everyone involved."

A fourth new site, Agenis, promises to save sellers hundreds, if not thousands, of dollars by creating competition for their listings among agents. At no cost, it allows sellers to request bids from agents, who presumably will offer to sell houses at a discounted commission or rebate a portion of their fees at closing.

And finally, yet another startup from the BCRM Group will finance the earnest money buyers attach to their offers, thereby allowing them to sign contracts and proceed to closing without putting up any of their own money. Deposits can be up to 10 percent of the purchase price, but BCRM will charge only 1 percent of the price to advance the deposit on your behalf.

Remember the "k-i-s-s-i-n-g" song from when you were a kid? "First comes love, then comes marriage, then comes a baby in a baby carriage."

In the old days, a mortgage usually came after the baby carriage. But fast-forward to modern times, and many couples are buying a house together before getting hitched. Changing the natural order of things could be a big mistake, warns Matt Parker, a Washington real estate agent who hangs his shingle with Keller Williams Puget Sound.

"While the numbers and studies are complex, the reality of a successful, mature partnership is not," says Parker, author of "Real Estate Smart: The New Home Buying Guide." "Make a firm decision on your relationship before you make a firm decision on your home."

Even co-habitating without a legal agreement is not a good idea, Parker writes. The numbers say that living with someone before marriage equates to lower marital satisfaction, more marital conflict, higher rates of infidelity and a higher likelihood of divorce.

"The relationship should come before your housing choice," Parker told me in an interview. "Getting out is far more difficult then getting in."

So fast-forward again, past the courting stage to the point where you're talking marriage. Admittedly, that comes much later these days than it used to -- so much later, in fact, that the prospective bride and groom may have created their own significant assets by that point. Perhaps a prenuptial agreement is in order.

Will that prenup impact your ability to obtain a mortgage?

Usually, the answer is no, says Karen Linehan-Wilson with 1st Advantage Mortgage in Lombard, Illinois. Generally, lenders do not ask about prenups. Barbara Sparks, with Envoy Mortgage in Houston, mostly concurs. Prenups "are acceptable," she told me, "as long as the agreement is court-ordered and complies with state laws."

Divorce is another thing entirely. The statistics aren't great. If there are children involved, buying a house after the split -- even long after the split -- becomes much more complicated.

When a would-be borrower has a divorce in his or her history, lenders want to see the marital settlement agreement, says Matt Weaver of Finance of America Mortgage in Boca Raton, Florida. Specifically, they are looking to see if the applicant pays or receives alimony or child support. As far as the underwriters are concerned, according to Weaver, there is no difference between alimony and support, even though support is usually tied to the age of the child/children.

If you have been receiving either type of payment continuously for three years and will continue to receive it for at least six months, says Weaver, you can count it as income. Of course, it must be verifiable, says Sparks. For child support, she says she confirms the children's ages to be certain the payments will continue for at least 36 more months.

If you pay alimony or child support, on the other hand, it counts against you in your debt-to-income calculation -- "in totality," says Weaver, no matter how much longer you have to pay.

Well, almost. If you have six months or less to go on your support payments, it's possible to make an exception. But otherwise, no.

"It's counted just like a car payment," says Weaver. "It's a liability that's no different than any other type of installment loan."

A copy of the divorce decree or court-ordered support payment is necessary to verify what you are paying or receiving. And if the terms of those documents have been modified, Sparks cautions, "a fully executed court order" is required to confirm the changes.

If your former spouse is paying inconsistently, you're going to run into trouble. If the lender cannot verify that you are receiving alimony or support payments regularly, month in and month out, you won't be given credit for it as income.

Another common problem with these kinds of payments is shared expenses: for example, jointly paying for the kids' braces. If your ex pays the orthodontist instead of you, it upsets the monthly verifiable trail of support payments. Here, Weaver says the important thing is to keep the trail intact: You get the money, and you pay the orthodontist.

One more possible challenge: If you want to buy another property while you are still in the throes of divorce, you should execute a "quit claims deed" to your current house and your soon-to-be former spouse should sign a release of liability.

If the split is less than amiable, good luck getting your ex to sign anything. Weaver calls that "a common cause of frustration" for the once-married borrowers he sees.

That's why he, like Parker, says not to rush into homeownership with your current love. Give it some time.