Absolutely not! Very fair prices, I think, since most prints that size tend to run $20-40 anyways. Besides, art is always priceless and we have too many struggling artists these days as it is because manufacturers will mass reproduce these for 50¢ a piece, and sell them for $5. You're selling your time, your talent, your words and a visual representation of yourself and your feelings. The very least you deserve is $20.