It calls for right at about 4.1 hours labor and approx $132 in parts. So depending on what the shop charges per hour, will determine the final price. The dealer will charge around $100-125 per hour,,,so using that as an example, the total for both the belt and the pump would be around $500-600.
Yes, that is a real good idea. The prices above are with the timing belt included with the water pump.