1997 nissan quest timing belt replacement?

I recently bought a 1995 Nissan Quest with 123,000 miles. Because it is used and I don't know if the timing belt has ever been replaced, I have the same question.
I have spoken to 2 Nissan dealerships in the area. From what they have told me, both recommended that the water pump be replaced at the same time due to the amount of labor to change the timing belt alone. Replacement of the water pump at the same time, however, does not appear to be required. Both dealerships quoted similar prices: $550 for the timing belt, $850 for timing belt and water pump. I have the Haynes Repair Manual, and it does not appear that the engine needs to be removed.
Interestingly, my wife drives a 1993 Toyota Camry. She had the water pump fail. As a result, the timing belt also broke even though it only had about 50,000 miles on it at the time. Fortunately, Toyota engines are not damaged when timing belts fail (total repair cost $801). From our experience, water pumps do fail, but I can't imagine that they fail all that often (how many people do you know who have had water pumps fail besides us?).
Let us know what you have done in the end. We are also still deciding what to do.

Rob
September 2005