I've gotten a quote for $120.00 per wheel for fixing scrapes and refinishing and $100.00 per wheel just to refinish. This was a place here in the Detroit area, but this might give you an idea of what you should expect to pay. Check you yellow pages under wheels and see if you can find a wheel refinishing place locally, you might even want to ask some car dealers since they use those places all the time. Hope this helps.
Fred