I would multiply those prices by 4 or 5.
I like to get paid $15 per hour. Obviously, I can't do that very often in quiltmaking, but my time and skill are worth money, just like that of a plumber, teacher, musician, secretary or any other person.
And it's not even that all my work is "art" - some is, of course, but really a lot of quilting or sewing is not creative. It's skilled labor, and it's something that not many people can do.