I do occasionally make commissioned quilts, but don't really make much profit if at all, if you add in your costs and time. People just don't understand what goes into a quilt because they can go to Target, WalMart, KMart, etc., and buy a bed size quilt with shams, skirt, etc., for under $150. They don't take into account that YOUR quilt isn't going to fall apart the first time they wash it.
If you're doing this to earn a little extra money, I'd have to say try to find a part time job.