Before deciding to charge for any quilt you really need to figure out what your time is worth to you, a ball park materials need and quilting/ binding charges. There are many different formulas used. Some people choose to charge by the square footage of the quilt, some triple the price of materials, some ( who are experienced and know how long it takes them) are pretty good at estimating their time & charge a rate plus materials. Everyone is different, has different requirements, needs and feelings about it. It is something You need to figure out and discuss with the customer Before starting any project.