There are so many ways to approach pricing, and every quilt is different. Different sizes, different complexities, different quality fabrics, etc., etc. It's hard enough to price the quilt you are currently making or have just completed because all your costs and your time are fresh in your mind. ptquilts (above) had it VERY right when she said that 20% is quite low. When I showed some of mine to some quilt shops a few years ago they wanted 50%. Yes, try a few with what feels like a reasonable, or slightly more than reasonable, price and see how you feel when you sell. There's no right or wrong, of course. Just what you are comfortable with.