good advice so far, I would show one to the shop owner and ask what they would want to sell it for, and what they would pay me for it. Then decide if I want to do it for that price.
After years of selling quilts on consignment, we finally got out of that and would never do it again. Final straw was when a shop owner "lost" a full sized bed quilt and felt it was OUR responsibility somehow. She did wind up paying for it, after a lot of debating.