When asked, I quote $25-$30, depending on what the person is wanting. Much like a CPA, Dentist, or Hairdresser, they are paying for the "Knowledge" you possess. If they provide all the materials needed my time charge doesn't change.
Sadly to many women sell themselves cheap. I haven't had any takers as yet, although some of the folks have asked to buy quilts I've already made. Again, I price them by what they're worth. A LOT.