A good friend of mine of owns a powdercoat shop in New Haven,
Most of the cost in the common colors (blacks, grays) is in the setup and they run black stuff all of the time.
When I got a quote for Frank the Dog we were looking at about 30-35 a wheel and I believe that included sanblasting and a clear coat.
I also remember Marc (my friend) mentioning that they could bring the cost down in volume to near $25.
PM me if you need more info.
John