Cost of material for top and backing times 4, plus cost of batting, plus my normal price for whatever quilting I do, plus $0.25/inch for binding. People don't understand just how expensive the materials are or how much work goes into piecing and quilting a quilt, so most are quite shocked at the cost for making a quilt. Your time and talent are worth lots more then most of us are willing to charge, but if they really want a quilt made especially for them, they should be willing to pay what it is worth.