the belt should only be about 10-20 bucks at like oreily's or napa
a water pump prolly about 100 or so
you can do it yourself for free given you have the knowledge or can find a manual on how to do it. Its not that difficult but I understand if you don't know a whole lot about cars
Your probably out of warranty at 120k miles so it would be more saving doing it your self ideally or having a differnt mechanic shop do it