Jason, sounds like you're working with bad data.
The 10.2:1 pistons increase in compression can be matched by using the lower comp pistons and shaving the head more. Low comp pistons and a head shaved to 22.62 mm will get you competitive HP. Proven.
Don't search craigslist or ebay. They don't speak our language or know our parts. Go to 944 specific guys like Mark Pleiman, Elliot Grafton, John Graves, or myself.
You can't be competitive without a short 5th. You can be competitive without an LSD. Proven.
We need to allow all racers equal access to equal HP/TQ, not equal access to 88 pistons, or a replacement part. We have equal HP now with STOCK pistons. Proven.
By all accounts, Dirks built solid, legal, competitive engines. $10K is not outlandish at all for a well-built 944 Spec race car with a good engine. There's no "designer" engine mark up there so I'm not sure where you were going with that comment. The only times I've seen junkyard engines installed were when racers had no choice due to schedule or budget constraints. None ended well. Again, not clear on your reason for that comment.