I assume because of the selling price, right?
I saw may peeps who thought selling 95% of their purchase price or when higher the current asking price is a good asking price for an used graphic card.
My stuff sold well with 60 to 70% of the cheaper of those two prices.
-- RMA such cards. Hidden defect which was unknown at point of purchase as 100% refund if you are based in central europe. The only thing I would accept an RMA when gigabyte would be open about such issues. As gigabyte stays quiet i classify the problem as hidden defect. It would be much different when gigabyte would went public. When they had put on any subpage of their graphic cards a note with that problem, e.g. tech specs, pictures, generic overview it is not an unknown issue anymore and the consumer most likely has to go the RMA route.
Yeah if my second card starts degrading even on just core I will RMA again but will not send the card until I have written confirmation of a refund.