Actually, the trac does come with platinum plugs, that's why they are recommended to last 100,000k prior to the first change. $55 is about right for the plugs alone, assuming they changed all six. In fact, down here, the dealer sells the plugs for the trac for about $10 apiece. The big question is whether they actually changed the passenger plug nearest the firewall, as this has been questionable in the past. Don't want to worry you but it has come up as to whether they change it or not.
As far as getting ripped off, were you willing to do the work yourself? If not, what all they did should justify the price. Keep in mind, labor is about $72/hr last time I checked. Changing the plugs will probably constitute an hour of labor, it took me about two hours without rushing. That part of the service alone would be about $130. As far as everything else, they probably charge more for the amsoil than you would find on the street. Plus whatever else they did. I revert back to, were you willing to do the work yourself (with the exception of a tranny flush), if not, then it was probably worth it.
