Exhaust, like tyres and brakes is a wear item which we can all expect to have to replace. I had to replace my entire exhaust within my first year of ownership. On an old car the battery must be suspect too, so the first sign of problems, get it changed. I had to replace mine.
I also had to get my gearbox bearings replaced, but all told the car has been very reliable, and, even with the added costs, still pretty cheap to run.