Well, I got my hands on a 2M piggyback card but not by itself. The last one that appeared on eBay went for a whopping $400. So I spotted a complete Intel Inboard 386/PC for sale with a 2M piggyback daughter card for $78 which was bid up to $260 - still expensive but I plan to keep that one and sell my existing Inboard/386 PC without a daughter card as a complete package (cable, drivers, doc, packaging and a 386 math co-processor, tested and verified) on eBay to offset the cost. I am not sure what it should sell for - there is one for sale on eBay now for $250 not as complete as the one I plan to sell, but that's a pretty good price given earlier ones went for quite a bit more.
Regards,
Mike