Considering what the cost of a secondhand a12 is worth (good runner for $100-200 and a running smoker for $50 or less) Its not a huge expense to just do an engine swap.

If you cant justify that much, and the car is clean a tidy looking, like the pic, then just sell it as is, with dead engine. I could even take it off your hands if you get desperate. (im not converting to pogo-stick mike your safe)

personally, I would have a mechanic double-check to make sure that the problem is as terminal as you think. If so, just do a cheap engine swap and keep driving it.