Since the full schematic and parts list is available for the RFD-1 could someone knowledgeable venture a guess to what a minimum production run would cost? I think they are the best demodulators with auto switching between AC-3 and digital audio. There is one on ebay right now the seller is trying to get $444 for. I haven't gone through the ic's to see if they are still available...
If the ic's are still available, a production run of the silkscreened board would make a great start for a DIY project.

The only IC which I would expect to be difficult to get would be the one which actually does the demodulation. Minimum orders for that kind of thing, though, are sometimes surprisingly small — 100, I think, was the number a friend of mine was quoted for an IC which died in her favourite LD player. Beyond that, there may be issues with Dolby Labs licensing & the FCC (Part 15).

Where are these schematics, I would be interested in making one myself.

http://www.lddb.com/_misc/manuals/AC3RF_Demodulators/Pioneer_RFD-1-EN_Service_Manual.pdf

Julien