I really wouldn't call it a moneypit because it really isn't. You're in the same boat as me, fixing the things the previous owner didn't do. Its really a great car once you get it to where it needs to be. Unfortunately, it just takes a while to get there but it will be worth it in the end.
I was in your shoes about to sell my car amonth ago, but then for one day, it ran perfectly and i had no issues with it and remembered all of the reasons i bought the ar in the first place. Unfortunately, i still stare at every Mazda 3 and Volvo S40 that passes, but i know i'll NEVER own one for the simple fact that its not a Vw, Audi, Porsche, Bently, Seat, ect
Ok, now to the problem. I highly recommend you just take it to a Vw Mechanic (NOT THE DEALERSHIP UNLESS YOU WANT TO PAY FOR OUTRAGEOUS LABOR RATES) near you.
Here is a list of trusted local mechanics listed by state. They are TDI shops, but iirc, most of them will work on the gasoline engine ones too. They can inspect your waterpump and timing belt too.
I STRONGLY doubt its ever been replaced and now is the time for you to start saving up for you to get it fixed. I JUST dropped off my car to a local VW performance shop (with a lot of the cool people I've met at the local Wednesday GTG) and the total cost of mine was $427.17 for parts AND labor. Its not too bad if you find the right place.
To sum it up, take it to a shop first and then go from there.
Good luck and hopes this helps.