I would call around. I was getting prices on coating engine components and made mention of having the wheels done. I was quoted $60-100 each for basic coatings and as much as $150 each for 2-tone metallic.

It's also going to depend on what kind of competition you have in your area. The highest prices I found were in Baltimore and the lowest were in Philadelphia. The local shop, Powder Barons, was in the middle at $75 each.