In terms of dollars, a home is worth no more and no less than what the market is willing to pay for it within a given time frame.  Market values, in the broader sense, can be affected by many things such as time of year, school district, interest rates, taxes, unemployment rates, etc.  These things can work both for and against a seller when he or she is trying to sell their home.  Likewise, individual attributes of the home, the neighborhood, and the location come into play as you drill down to assess the current value of an individual property.

Homeowners can get a rough estimate (+/- 5-10%) of the value of their home on their own by evaluating the recent sale prices of homes in their neighborhood.  Real Estate Agents, with their access to the Multiple Listing Service (MLS) archives and general understanding of the market, can get a more exact estimate (+/- 1-3%).  Nobody can get a perfectly exact number no matter what they might tell you.  Needless to say, though, when you're talking about the value of a home, the small percentage difference between the rough estimate and the more exact estimate can add up to either big money left on the table or a lengthy, and potentially stressful, selling time.

This is where the human factor comes into play.  Getting the most exact number possible allows the homeowner to set his or her price AT, ABOVE, or BELOW the likely true market value in order to serve his or her time frame or financial requirements.  Basically, it gives the homeowner more control over their future.  If a seller knows the average amount of time it takes homes to sell a home in their neighborhood and they know, as best they can, what their home is worth, they can affect the amount of time it can reasonably be expected to sell their home by adjusting their sell price.  Deviations in offering prices above the market value will take longer and deviations below the market value will take less time than the neighborhood average.  The greater the deviation, the greater the difference.  However, we must take notice of the fact that since most homes are sold by real estate agents, the average market time for homes is very heavily influenced by the exposure they receive when the listing agent puts the home on the MLS.  The 'For Sale By Owner' approach can work in certain "hot markets" but due to its significantly lower exposure rate and its inability to filter out buyers who are not financially qualified, has been clearly proven to require a substantially greater time to affect a sale.  As such, the clock really doesn't start ticking until the home is listed on the MLS.  So the biggest question of all is: How much time do you have to sell your home?