A fair market value is a guestimate of what your house may be worth, based on what has sold in your immediate neighborhood. It give you and idea of what you get for your house, in the current market.
An appraised value is the value of your home, based on the appriaser's measurements of the home, and sold acitivity in your area, condition of your home etc. The appraiser is coming up with the value of your home, usually for the bank, to see if the bank can loan you the money, based on the value of your home.
They will onlly loan you the money upto it appraised value, (certain exceptions may apply).
If a seller is selling to a buyer with seller financing, than a fair market value may be Ok if both buyer and seller agree on terms and condition, an appraisal may not be necessary, although recommended.
I will be glad to do a fair market value for your property.. please feel to contact me.