Wow! If they're worth that much why hasn't somebody figured out how to clone them?
The problem is that they're only worth that much to a very small number of classic Amiga enthusiasts. If these were to be re-manufactured in significant numbers (significant as taken to mean >200 for example), then no company would be able to shift them all for that much. The price would have to come down significantly, to <£500 I would guess.
Re-manufacturing the old BPPC and CSPPC cards would be the cheapest way to go, but this would involve obtaining all of the design information. It would be good if we could obtain this information (even from a self interest point of view), but I doubt they will ever release it unfortunately, which is a shame.
Assuming we did obtain all the information necessary to re-manufacture the boards, then we'd have all kinds of obselecence and Rohs compliance issues to deal with as Kronos has already mentioned.
The better way forwards would be to develop a completely new PPC accelerator. But then you're talking about significant design costs, which would need to be recouperated in sales. There's probably not enough money in the current market to do that, and that's why nobody has come up with a PPC replacement so far.
It seemed like Elbox had got pretty far with their SharkPPC cards. I'm not sure why these never gor released, and it is a shame for sure.
AH