Fannie Mae is overpricing prices of properties all over United States, I am realtor, sellers are going to foreclosure

Fannie Mae is over pricing properties, turning down real offers we realtors received at fair market prices. Please we need help, many people are going to foreclosure because of this. Last month one of my clients suffered this, he owed 260, 000, comparables were 230,000 and Fannie Mae asked us for 307, 000 ,