I had the same feelings as you, I went to my dealer for a 30k.....they wanted $800....I laughed and got back in my truck.

I went to a Econo-Lube and got....

New fuel filter
Flushed and changed out trans filter and gasket
Front and rear Differential
Oil and filter

$300....and watched them do it.

I'm not very happy with my dealer, I asked them to fix my window recently for the forth time(amonst other stuff) while I was out of town. I spoke to my service adviser while I was out of town and he said the machanic said he did'nt notice anything wrong with the window(it was clearly sliding off track). I told the adviser that, hoping he would fallow up and check it....got back home, picked up my truck.....the window was the same as I left it...jerk-offs!