How about $400? No, seriously...
986 five-speed tranny - unmodified Audi 012?
There. Saved you at least a thousand.
I was once looking around a junk yard after I had done a clutch job. I was among the transmission section helping a friend look for a transmission for a Mitsubishi Eclipse and noticed how similar a transmission on the shelf looked like to mine. As a matter of fact, it was the same, and it was labelled under the Volkswagen shelf.
If you actually take a look at your transmission on the Porsche you will see the volkswagen/audi logos on there!