It is true that non-quilters do not understand or appreciate the amount of work that goes into making a quilt.
I would never do commission work, but if I did, my contract would have a big disclaimer stating all work is a one of a kind, hand made, custom design that requires many hours of tedious work and quilting talent to complete. The cost of materials would be collected up front, and the customer could see the design wall display, but any change requests would incur additional charges. Once construction started, customer would agree to accept the quilt as delivered. Failure to pay for and pick up the work by a specified time would result in forfeiture of the finished quilt as well as the advance deposit. And I wouldn't work for cheap. That is why you don't see quilting as a career. We can't really get the money that we deserve for producing this custom product.