because i bought my 90 tsi for the same price with the SAME EXACT problem.
the car is definately worth that price. you just need to find out how severe the problem is. does he mean part of the bellhousing on the tranny is broken and needs to be welded back on? extracting a broken bolt from a block isnt the easiest thing. if its one of the smaller bolts you can most likely live without it. just make sure you know what your getting into before you buy it.