Janet, You didn't say if you wanted it machine quilted or hand quilted. I recently paid $165 to have a king size quilt long armed in my community. The quilter was a friend and she just did an all over design on a pieced star quilt. I bound the quilt myself and provided the backing and batting. A long armer also needs a bigger backing in order to load it on her machine.
If I had been doing the same quilt for a customer, I am a professional hand quilter it would have been a minimun of $.10 a square inch or at least $1000. I also charge extra to baste and bind. I would also charge you at my cost if I provided the back and the batting. If you wanted a special quilting pattern, say in the borders etc. I would charge a small fee to mark the pattern for quilting.
As a lifetime handquilter I think a twin size quilt would be an easy place to start for any quilter.