That is pretty cheap. I have been powder coating for about 15 years, and I wouldn't do rough wheels for that price. By the time you clean them, blast them, clean them again, run them through a heat cycle to out gas them, and coat and cure them, there is too much work for such a low price. Plus there is the cost of materials, electricity and wear and tear on the equipment. I usually charge $75 - $100 each for wheels. If you have a person coating rough wheels for that price and doing a good job, they are a great treasure. Here is a motorcycle luggage rack I did for a guy a while back. I love powder coating. It is great to have a fun hobby that can actually make some money.