Its a lot of work and costs accordingly, but it can be done yourself if you're mechanically inclined and have the FSM. You can do it w/o the special tool, but the tool makes the job a lot easier (costs about $40). Shims are a few bucks a piece ($9?) but you can usually get away with swapping a few around instead of buying all new ones. I ended up adjusting about 6 valves (all exhaust valves), but only bought 2 shims since I was able to swap the others to get them into spec. The dealers usually stock them and there are quite a few different sizes, so I don't know what would come in a $30 "shim kit." I just did the measurements, bought what I thought I'd need, and returned what I didn't.