I payed similar prices (compared to our standards). However, each color is separate price.
At "my" local powdercoater (who I did find through Google by the way) it's best to give a whole bunch of parts in one go, as it doesn't matter for the price. It also helps a bit that this guy always seems to forget to give me a bill
F.I. I payed the same for the grey Midway coindoor as I did for all the little black parts of the Galaxian and MB.
Wish I could do it myself. Powdercoating beats all the other options IMHO. I'm in a marching band and we've had a number of rings and drum hardware powdercoated black that was originally chrome colored. It's been done 3 years ago, and there's not a chip or scratch to be found, and really, these drums are not always treated friendly.
Powdercoat metal parts on a cab, and I bet they'll last as long as you live....