looks like I will have one of those major repair costs on my 8 now.
My auto gearbox is in a very bad state at the moment, and I planned to take the spare one I have and have it rebuilt, and then simply do a swap.
I have been in contact with a company that are specialists in auto gearboxes.
at 3200 euros they will completely rebuild my gearbox to as-new state and give me a 2 year warranty.
an extra ~1700 euros for the swap, fluids, flushing oil cooler system in the car and bench testing the gearbox.
making the total 4900 euros.
At the same time I will have the rear engine seal ring and the oil sump seals replaced. parts cost is about 150 euros, plus the work to have it done, I expect another 400 euros there.
That should bring my total up to ~5500 euros, though I will have a car that does not leak, and won't leak for many years to come, and my gearbox will be as when it came from the factory and should not give me any pain for the next 10-20 years.
Guess I'll just have to dig deep and forget about it and just enjoy the car when it is done.