I know dealer service centers like to do things like take a loss on oil changes and similar services to get folks coming in the door regularly, but that's not usually the case with real labor/service items. I had my timing belt/water pump/tension pulleys/etc done last year by a local independent shop, after pricing it out all over town. The dealer was actually the cheapest quote, by just a little bit, but I had heard to many bad stories over the preceding 3-4 months to feel comfortable going there (recent change of ownership and a total leadership change at the same time; not uncommon for stuff to be in flux in those situations). But, the quote for the parts alone was more than $350 at the dealer. Are you sure they gave you a total service quote, and not just the parts (belt, pulleys, water pump, etc)?