I have no idea, but I would definitely get a contract signed and be sure to let her know that this isn't a project that can be done in a couple of days or even a week. That all quilting takes time, and your time is as valuable as those in plumbing, electrical, automotive repair, etc. and they always charge an hourly rate for labor, plus parts. When I decorated cakes for the public, I charged by the slice, plus extra for extra decorations, roses, lattice, etc. I once had a lady who wanted a wedding cake done and when I quoted her a starting price, she thought I was too high. Her husband was a locksmith and I informed her my time was as valuable to me as his was to him, and he charged for parts and for his labor. She went somewhere else, but I didn't lose sleep over it. You also need to include the factors of thread, batting, backing and whatever else that is not included in the kit. Your labor is worth a lot my dear. I don't think $800 is at all too high, maybe just a little low. I don't quilt for the public because most don't want to pay for your time and ability. If she isn't happy with your quote, then too bad. Do you really want to do this particular pattern, if you don't please do not commit yourself to something you will regret getting into.