One more unsolicited opinion. I have bought plenty of cars like this for up to $2,500, then decided if I wanted to part them out of fix them. It may eventually get an offer acceptable to the seller, but the pool of buyers for a car like this is small even with all of the work that has been done.
The seller's valuation, by parts is only relevant if he breaks it down and parts it out. That would be sad, but more likely to move the car for the desired return (minus all of the labor and time that goes into parting out a car.
I agree with the others that the best option is to fix it. A suitable used Tiptronic can be purchased for about $2,500. If you plan to keep and enjoy the car long term, a quality rebuild may be a better option - as
Starter and
Adrian have done.
Car-Part.com:
If I was local, I may have offered a bit over $2.5K because I really like the black with a good red interior, but I'm full up on projects and have no time to catch up on them.