I don't think 25-30 is bad for mounting and balancing . If you think about it some shops pay between 5k-10k for a machine and thats just to mount the tires figure another 5k for a good balancer .So a shop has between 10k-15k out of pocket plus the cost to pay the guy that doing the job oh and wait electricity tax's and so on .
At the shop i work for i make good money and we do good work and are one of the cheapest places in the area . We started to charge 20 a mount and balance if you bring your own tires . If you buy tires from us its like 15 total . 7 to mount 8 to balance if you buy from us .

I just love how people love to look for the cheapest place remember the saying " You get what you pay for" it works in this case too .