You could do it yourself if you got patience. Took me about four days.
I painted some pitted chrome/black rims. Can't really tell in this picture but they were shot as ****:
Washed them with soap.
Dried them.
Sanded them down with 80 grit until I couldn't feel my hands.
Then I sanded them down again with I think 220 grit until the rims looked like shit.
Wiped them down & sprayed a layer of etching primer then a few layers of automotive primer & wet sanded it.
Then I did a whole can of Rust-O-Leum gloss black paint per rim, I let about an hour pass between coats.
Then I wet sanded whatever needed to be wet sanded.
Then I used about two cans of Duplicolor clear for all four rims.
Lower left is before, top right is after (this pic was April 2011):
This is the rims now as of October 2011:
Those white lines are tire foam. No rock chips, cracks, & hasn't faded at all. When it's all cleaned up it matches the onyx black almost perfectly. These 22's are my winter rims though which is why I went this route. Someone on GMFullSize went this same route with his NNBS chrome bumpers & he had the same satisfactory results as me. Just depends if you got the patience. Lol.