This seems obvious yet it hardly is ever talked about. That is to some extent because most homes are not sold for all cash and without financing. Therefore, a bank is involved  and they will want a verification of the homes value. 

This is called an appraisal. So the ability for you to sell your home is largely determined by the availability of  of financing.

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Realty Times "Choosing the Best List Price, August 25, 1998"-"[Your Homes Price] is determined by the combination of the seller's unique home and situation and the buyer's situation. In other words, the market is created house by house." 
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There are various means to help to best evaluate the going price for your home.

The article entitled, "Pricing Strategies" can help you with some some ideas on how to strategically determine  your home price. 

real estate comps

Real estate comps help determine your home value. By using comparable home sales or recent real estate sales prices and supply and demand, and  available financing. Also an appraisal can help determine your home price.

online home appraisal free

Online home appraisal resources are found via the MLs and comparing available and sold properties. Free home appraisal.

A free online house appraisal is provided by many service oriented realtors. Often time a realtor or appraiser will use recent home sales to determine value. Many realtors will offer a free online house appraisal whereby you can get an idea of your homes value.

What is the value of my home ? Recent home sales help determine the value of a similar home.