ak1 is right on the money with his post on this page.
In his post, he said……….”If this person is desperate to sell, the other seller, 50 feet away, is going to have a heck of a time selling their house w/o reducing the price.”
The first thing that will happen is when you have two or more houses in the same neighborhood selling for “X” price, those selling prices become the new comps for the rest of the neighborhood (related to $$ per sq. foot/lot size). Unless everyone else who needs or wants to sell, they would have to either find a cash buyer who would be stupid enough to pay “X” $$$$ over the going price because they won’t be able to get an appraisal at a higher, per sq. foot price to show the lender. There are many people who are either ignorant to this fact or they simply don’t want to be objective about the true value of their properties.