I applaud your initiative but I would recommend that you rather looked into the 68020/30 project over at the EAB website.
68020/30 - RAM - ProjectThe reason 68060 accelerators go for 300 on ebay is because they are not taken off an assembly line. Flood the market and you will hardly make 300/board. Unless you plan to sell one every month for years to come.
The only "market" in my view is for the casual gamers who just want to play some games and tinker around a bit. the 32bit extra ram and a faster 020 or 030 is more than enough to do this while keeping it all at a reasonable price level. Perhaps around 100 euro.
