No way would I piece a top "give it away" for $20, 30, or so dollars.
Pieceing is a bear and depending on the design, type of fabrics used and time put into it no way could it go for so little. So so fabric goes for that much and better quality fabric about 3 times that amount and count in the hours one spends creating the design, cutting, etc. it surely would be alot more than that.
More power to folks that can get it that cheaply.