Different locations charge different amounts. Some charge by the inch, some by their time, some by the project. You will get lots of answers. I charge $20 an hour for sewing. Sometimes I charge $20-$40 to do a binding, if I have to prepare the binding ( piece strips, fold, press, machine to one side, hand stitch to other) I charge more than if someone brings me ready to stitch ( already pieced, folded & pressed) binding. And even less if they machine stitched it to the front & I am doing the fold over & hand stitch. Many factors determine price. Size of quilt, mitered corners, scallops, rounded with bias binding.... There is no simple answer. Check with a local shop & see if the do, or know someone you could check with to see what they charge. Or if you have a guild bring it up as a discussion at a meeting.