The fact these old PPC boards and graphics cards are getting such insane bids on ebay is a testament to the fact there is a DEMAND out there for them.
I do think a lot of people are buying them to hold onto now.
Even if only 100 Cybervision cards are sold on Ebay each year for $300 each, that's $30,000. Enough to at least break even on the re-run production. I personally think that if these were new boards (not used as on Ebay) even more could be sold.
If lots people are insane enough to spend $300 on a USED (possibly abused) piece of Amiga hardware with no support and no warranty, there are probably 3 or 4 other people who would be willing to buy a re-release of this hardware NEW from a reputable dealer with a return policy.
Not to mention the fact, that if original plans for the boards can be found, it might be possible to re-engineer them with a smaller, more modern design that is esentially a clone the original hardware in a cheaper, smaller and more efficient design (like the difference between an original C64 and the circuit board of a C64DTV).
Hell, if I knew I could get a new 060 board for my A2000, I would be much more likely to plop down $400 for it than risk that same money on a used one with an unknown history, from a person I've never met before (see the scams thread on A.org).
The Shark, Dragon, etc. are all vapourware so far....we have designs for older cards already that have software support and a tested track record. There is a demand for them if someone would just produce some more.