[T-sport]

Did you buy the car from a trader or private seller?

I would say whoever sold it to you must have known it was in a bad way and needed quite a bit of money spending on it ...

Whats the difference in price for the used or new gearbox ??

What mileage you got on your tdi as the manual gearbox is pretty strong and not common to be knackered like the Auto boxes ?

Could be a synchro mesh problem with the 5 th gear selection issue which can be fixed cheaper than replacing the box !!