Audi: Broken A4 driveshaft = broken auto gearbox?

I was about to sell my A4 (95, 2.6, 94K km) when the driver's side
driveshaft suddenly broke, leaving a bearing on the road. Fortunately
I was able to bring the car to an immediate stop and have it towed
home.

My mechanic is telling me that there is about a 50% chance that the
driveshaft breaking may have damaged the auto box. He says there's no
way of knowing if the box is damaged until the shaft is replaced,
which leaves me in a bit of dilemma. I am willing to pay for a
replacement driveshaft, but if the box is also damaged then I would
prefer to scrap the car as the cost will be higher than the car is
worth.

Do I can take the chance, pay for the driveshaft replacement, and hope
that the box is OK?

plenty wrote: 
How about getting a secondhand driveshaft from a breakers, and fitting
that? (you could look for an autobox too......). I would have thought
you could even get a shaft and box from a breakers for less than the car
is worth, surely?