By definition, fair market price is realistic. That is, your house is worth (and should sell for) what is commonly called a "fair market price." What a willing buyer will pay, and what a willing seller will accept.
However, if by "fair market price" you mean your tax assessment (as Jean has guessed), then no: a tax assessment is not a realistic number for the value of your home. I disagree with the advice to price near or at a tax assesssment. Your tax assessment very likely wasn't based on any sort of individual review of your property. Also, it's likely to be out of date--it probably was done/calculated anywhere from 6 months to 3 years ago.
Others here note that buyers are looking for bargains, thus suggesting that "fair market price" is somehow higher than what you can expect to get. Not so. "Fair Market Price" should take into account market conditions and peoples' expectations. After all, as Linda correctly says, fair market price is what the market will bear. So, let's say you bought a home 10 years ago for $100,000. You could have sold it 6 years ago for $200,000. Two years ago, an identical house down the street sold for $125,000. You go online to one of those online home valuation programs (you plug in the address and it Guestimates what your home is worth) and it says your home is worth $95,000. The tax assessment is $120,000. Last week, an identical house next door to yours sold for $115,000.
What's the fair market value? Probably right around $115,000. What you bought it for doesn't matter. What you could have sold it for doesn't matter. What it's assessed for doesn't matter. What an identical house sold for a couple of years ago doesn't matter. What an automated online calculated Guestimates doesn't matter. What matters is what someone is willing to pay today for your house. And probably the best gauge of that is what similar houses recently sold for.
Ask a Realtor to do a CMA (competitive market analysis) on your property. He or she will take a look at similar properties near years that have recently sold. Based on that, he/she will tell you, within a pretty narrow range, what your house is likely to sell for. That's about the best you can do. But that'll be the realistic number.
Hope that helps.