My old company (now self employed) but still do work for them currently have 4 seagate "warranty repair" drives in stock.
It would be much less of a problem for the retailer if they kepts the same labels, how does the retailer get rid of them.? The only answer is to sell them as "used".
As far as the buyer is concerned, be aware that people will try to sell you stuff that they shouldnt, only ever buy new unused equipment unless you enjoy risk taking.
Essentially its the drive manufacturers that win because many dont bother returning them because of cost and hassle, others dont even realise they have a warranty, some give up after retunfing the drive a few times and keep on getting dudds. The manufacturers who treat their customers well will keep them.
Main PC, P180, CM Silent Pro 500M, i5 3570k @ 4.2Ghz, 8-GB @ 2,400MHz, 512GB 850 EVO, 500 Extreme II, 2x 2.5" drives, MSI 660Ti Twin Frozr.
Server, under reconstruction, 380W Enermax Pro82+, positive pressure only.