How much would it cost to replace a roof on a 1600 square foot home?

It is almost impossible to answer, depending on pitch, dormers, valleys. Get an estimate

from homedepot, then you should be able to get a real good roofer that will do it for almost 1/2 the price they quoted you. I had a customer call them and was quoted 18,000.00 I did it for 10,000.00 with 30yr shingles wind rated, new felt,, ice/water

barrier on all edges, top of the line ridge vent.