Well I have done a few of these 90 k services and it does vary from dealer to dealer. I just compledted one on a 99 lexus and the coolant pump was leaking out the weap hole and the tensioner pulley was making noise, with the idler making less noise. I did replace the tensioner as I was lazy (maybe in away, but the new tensioner is smaller, maybe not to put as much tension on it to wear the Pump and other bearing). Any how, If you trust the mechanic or its your own labor then it may be a good choice to not do some thing. But if you are depending on it then maybe it is better to pay the price.
To do both the water pump and the t-belt is 8 toyota book hours. the part can cost (my cost not yours maybe C-dans also) about 300 for all the tensioners, belt, bearing, water pump (my cost is about 88 dollars). So if you can get the t-belt done for 350-400 what a steal(hopefully the shop is eating it, not the guy doing the job(he needs to feed his family also)) the water pump is a hour and what 120 with a generous mark up. so not too far from 279.
Some time it gets to me how people bitch about what it costs to do work on these vechicles as well as cars in general. The good mechanics have as much invested in training and education as most people that have their masters(maybe a strech, I have both). Then come in to play the shop owner(or dealer), he want a living and to pay the bills. Then the customer that want everything garentied for a million miles. I wish doctors or lawyers would give the same warranties that most shops give, they do not have to be right, but mechanics have to be or it is a waste of money or ther are mistrusted ETC.
any way my pet peve. Good money spent on a great ride that the service lasts as long as it does.
I just spent a day and most of a second doing a 90 k serivce. All fluids (even the hydralice suspension), repack the front bearing, front brakes, bleed brakes, replace tranny fluid, P/S fluid, engine oil, all diffs and t-case, tranny flush, coolant, t-belt and bearing, coolant pump, grease drive line, fuel filter, air filter.
O Yea, no spark plugs at this service (unless it is some thing else then the factory Iridum; Once at 60k(emission required), other wise up to 100 k miles per change). So factory time on this is close to 14-15 hrs, parts/fuilds close to 400+ in cost on material. So figure labor for your area and a mark up then you may understand the deals or not you may be getting in your local area.
good luck on your choice.later robbie