I don't doubt your logic, trag, but that is certainly NOT the way it works on EBAY! Demand for the "older stuff" is such the prices for a 400k external floppy drive are sometimes 10 to 20 times higher than a manual inject newer version! Even 800k drives are excessively priced on EBAY. I don't know that it's really a situation of supply & demand as much as it is sellers trying to create the IMPRESSION there is high demand, hence all their ludicrous claims of "rare and impossible to find elsewhere" and such. EBAY sellers themselves drive prices through the sky, more than demand. True, ignorant buyers are to blame in keeping this problem going. For indeed, if no one EVER bought at those nutty prices, the sellers would lower the prices or stop selling on EBAY altogether.
So again, it is curious to me that Shreve is pricing drives in just the OPPOSITE way that EBAY does. To me it indicates that Shreve is either an honest firm, pricing older stuff lower than the newer (as it should be in most cases), or they are deceptively hiding problems about the older equipment (very possible because older stuff is typically in worse shape than the new).
But so long as they have a return policy and if they pay for return shipping too, even if the drive is bad you aren't out anything. But if their shipping is expensive and if you get stuck with shipping charges for a replacement too, then you need to either ask more questions before you buy or go to someone else.
I am by no means trying to slander Shreve here. For like I said above, I would trust them above most EBAY sellers any day. But you still have to be careful and ask questions and read all the fine print before you buy an older, used item like a floppy drive.