Water pump, timing belt questions

Hi,

I'm interested in buying a used Jetta from an individual (v. a dealer) and preferably one with a manual transmission.

At what mileage should the timing belt and the water pump be replaced? Most of the cars I am interested in have over 60K in miles, but have not had either part repalced. Do I have some negotiating room with these cars since these major parts have not been replaced, or do they have longer lives that I was thinking (50K miles each)?

Please let me know.

Thank you.