I'm sorry-I misunderstood; thought it was going to be a school fair, not community (I had another blonde, senior moment). I think $15-20 is good, a low price, but probably what (nonquilting) people will pay. I was at a community fair and someone was selling runners; they were 2 pieces of fabric, no batting, sewn together and turned (birthed) right side out. She was selling those for $15.00. NO quilting or stitching, just a flat fabric runner.
Good luck-hope you raise a lot of money.