I don't long arm for the public and have never had a quilt done by a professional, so these are just some of my thoughts.
Color of thread
Are you to attach the binding
Fee for ironing the quilt top
Squaring up fee after quilting
Fee for stay stitching the edge of finished quilt
Fee for setting up scalloped edges
Action to be taken if borders are ruffly. (Actually, that should be checked before you accept the quilt, in my opinion.)