There is a single toothed timing belt that connects the crank, cams, idler pulley, tensioner, AND water pump. If the water pump bearing goes bad it can cause more slack in the timing belt than the tensioner can make up for, or it can cause the belt to track way out of line, or both. The result is piston/valve contact.

Given the monetary value of a car that age, if you have to pay a mechanic the repair the engine, then the car's current value is next to zero. If you can dig in and repair it yourself then the car might be worth a bit more than zero. Now if the car is loaded with good parts that you need on another one then that's a different story.