You should price the batting, and are you supplying the backing or just piecing it? I would charge for the material. My quilter supplies the thread and it costs about $40.00 for a large baby quilt. When I rent the long arm it costs about $30.00 and I supply everything including the thread. It would help you to quilt a bunch of quilts to get good at it, so doing it at a reasonable price would help you too.
Sue