Were they for the stock wheels?

Another factor that no one mentioned is the liability of the mount and balance. I am assuming you brought this shop your own wheels and your own tires. Therefore they are not making anything off of your tires, yet they are risking damaging you wheels. If they charged you the normal 10-15 per and damaged one wheel, they now lost alot on the deal. When you add up the materials, time and the disposal fees it has to be worth the shop to even touch the wheels. I dont think you got ripped off.