If you can get a dealer to do it for $500, get it done!
I was at my local stealership earlier this year for my '98 3.4. He quoted it at $919.58.
I visit the parts dept for work a lot, and the manager knows me now. I will prob get genuine parts from him (w/ discount), and have it done at a buddy's shop. There is no way i am having their service dept do the work.

oh, i have 200k on my rig. last one was changed at 102k.

 

one reason i want the dealer to do it is if they screw something up like snaping a bolt off they have to fix it now if i did that id be sol

 

well things might change my moms bf has a nice size shop and works at a john deere dealership so im sure he has a big tq wrench he could borrow

 

do it! you won't regret it. i definitely learned a lot from the experience- enough to feel comfortable to do it again at 250k+! any questions, i'm here- but it's relatively straightforward (as you've noted).

the only thing i recommend looking into is building the SST pulley holder, and maybe purchasing this (only if you're NOT replacing the idler pulleys/taking them off)