The last set I had done was a couple of years back now. To have something for the guys to hang the wheel on, it's generally easiest to remove the inflation valve from the wheel. I stripped the original paint off myself with paint stripper and a lot of elbow grease, then gave it to the guys to do the job on.
Had to wait for a time when they were doing a run of matte black stuff and the final cost was $25 a wheel. It'll probably set you back a bit more than this generally and even more if you want them to sandblast them too. I masked off the lip prior to giving it to them to have a polished lip though I wish I hadn't as while it looks fine, I should've protected it with a clearcoat afterwards as it's got a bit of oxidising from brake dust.
---dens