do the plugs yourself, its easy all you need is a wrench (and a shop manual might help give you some direction, chilton is a good one that is sold at most auto part shops)
I have had my water pump replaced and it did cost me $500 through the stealership. I would recommend getting an OEM pump through ebay or a part store that sells basically new parts like G&R auto parts their number is 405-634-0575 (they ship). They have lots of parts and I have used them to replace some parts on my car, its usually half what the dealer wants for (just the part) and I have never had any trouble with their parts (air condt. pump and a MAF sensor along with many cosmetic parts). The shop manual will tell you how to replace the pump it shouldn't be too bad, but it might take a while. If you want to save a lot of money do it yourself, and besides then you will have the satisfaction of saying you did it yourself!! haha! But if you dont want to do it yourself buy the pump yourself and have the stealership replace it for you it would still be way cheaper. (you also might want to check and see if you really need to replace the pump, what did they say the reason was? usually they are replaced if they are leaking).
Have somewhere like autozone check the engine code, its free. They will tell you what it means (if not then use the chilton manual, it has a code library in the back). Then decide if you can fix it yourself.
Last edited by Tahoe7689; 01-24-2009 at 12:39 AM.