I'm looking at a 2005 Audi a4 1.8T, 112,000 miles for my college aged daughter. Timing belt and water pump have been replaced. Will any future repairs break me?

Your budget, but, I think you might do better with an Asian car, just my opinion. BUT, having the timing belt and water pump replaced at this mileage in any car is an excellent idea..

At the current mileage of the car i would say you should be alright till close to 200k. Just keep up with the usual maintenance and the car will be alright for a long time. This car sounds like it was owned by a old person with such low mileage so it should be pretty good. the 05 models did not really have a lot of problems as far as i can tell. check out this link for any recalls and customer issues. It was one of the least complained about modals over the years. Its likely due to it being close to a final modal of that version of car. http://www.carcomplaints.com/Audi/A4/2005/. as long as you do regular oil changes every 8000Km / 5000Miles with castrol 5W40 Full synthetic the car should run very smoothly. when it reaches 200k Km / 125k Miles if its not been done already I would recommend a trany fluid filter and fluid change.