I just spoke to spectrum, if you want a colour that he has to set up specifically for you, you're looking at approx. $125. If you are going to do a colour that he is doing for something else (blacks being popular) he said it would be approx. $50.

If you're looking at black powder coat, he says he does semi-gloss at least once a week, and matte pretty rarely.

He does not strip the existing paint.

I called a few other places I found in the phone book and the cheapest I found was $125 for just the powdercoat. One place was a minimum charge of $500!

Update: I called Blast and Coat which is in Mississauga (905) 625-7739, and to do a black powder coat and sand blasting was $75. I'm not sure the cost of other colours.