"How badly do you want the house?" asks Jim Evans, a real estate agent in Louisville, Ky.

Knowing what to offer, experts say, takes research, some basic negotiating skills and a dash of courage. Ultimately, negotiating a deal boils down to how motivated you are to buy the house, and how motivated the seller is to sell it.

Several factors can influence your bid:

• Fair market value. You need to know what the house you want to buy is worth, said Evans, with ERA Kepple Keene Realtors.

"It should be priced similar to what similar homes in the neighborhood have sold for the past six months or year," he said.

• Days on market. Typically, the longer a house has been up for the sale, the lower you can bid, Mary Martin, another Louisville real estate agent said.

• Competition. In some cases, the home's listing agent will tell you whether there are other bids, although the agent might not disclose what those bids are.

• The seller's position. If the seller is under financial duress, Evans said, "a lower bid is very appropriate. It also depends on how soon the seller has to move out. The more desperate they are to sell, the more leverage you have, and the lower the bid should be."

A buyer can try to learn the seller's position by asking a few questions, said Martin Latz, an expert in negotiating, including: Why are you selling the house? How did you arrive at the selling price? What do you do for a living?

Other signs: whether the house is in foreclosure or in danger of being foreclosed; whether the seller is building a new home and doesn't want to own two houses at the same time; or if the house is being sold to settle a divorce.

When it's time to make the offer, buyers have three options:

• Bid low if you're not desperate, the house needs repairs and it's been on the market for awhile. After the first month, Evans said, a lower bid is appropriate as long as the home is priced fairly.

• Offer the asking price, if you think the house is fairly priced, if it's a new listing and for a good chance to have your bid accepted.

• Bid high, if you really must have that house or if there are other offers. With multiple bids, Evans said, you'll have to "play it by ear" in deciding how much to offer.

Bid low, Martin said, "If you have the courage to go home and say, 'Dear, I didn't get the house."'

That's what happened to Jason and Mindy Locke, who lost out last year on a home in Goshen, Ky.

Jason Locke bid $155,000 for a home listed at $159,000, because, he said, "I assumed you were supposed to bid low, that the asking price was negotiable." But the offer was rejected by the seller, who accepted a bid for the full price.