I just had something like that happen from a forum. Not here.
Bought a EVGA GTX 970 SC ACX2.0 for almost NEW price. (I jumped on this since the guy offered that I pay one large sum right away and the remainder in two weeks. Great, I thought).
A) Since it is used nevertheless I didn't have the 5 years warranty but "only" the 3.
B) Stepup I cannot do because I am not the original owner.
Turns out the card is not 100% "alright", it craps out under stress when I set power target to 110%. (NOT overclocked).
Now, the seller is making it sound like it was my problem because I ran "the card over specification" (Powertarget to 110% is not over spec for god's sake)...and the card also is SUPPOSED to hold it's mediocre STOCK boost speed of hideously poor 1380 at 1.212V. But it doesn't. (Overclocking here doesn't even come into play).
Now I have added costs since I live in Spain and RMA shipping will cost me €38.
I asked the seller to at least reimburse me a ridiculous €20 to cover some of the s/h for RMA...but he insists his card was sold as "flawless". (For me, Afterburner Power Target 110% == Crash, Reboot is anything BUT flawless. It's a fricking HARDWARE DEFECT.)
(As a side-note, what really *issed me off is how several people chimed in the discussion and basically saying a RMA would not be needed respective making it sound like I just want the RMA because it doesn't overclock. I KNOW that I could not easily sell this card again should I ever plan to do so, for sure not to those people who now claim that the card is basically "working as advertized". Those same people would then likely trying to haggle for a very low price, pointing out that it has a problem...LOL. Sorry for ranting...)
Then, some months ago I bought a 4770K which upon inspection after I took it from the board indeed had 3 or 4 of the gold pins flaked off. The CPU is good, by pure coincidence the missing pins are not important.
On forums and ebay etc. I am probably gonna be more cautious because I more and more get the impression that people are "selling off" underperforming or semi-defective hardware.
Rest assured, those some people would also charge PREMIUM for those parts which they tested and where they know they overclock well etc. (Like i7 for €350-€400 because it's a good overclocker).
SOME people I see buy and sell hardware in such high numbers that it's clear to me they're doing this for finding good parts that overclock well, means whatever they sell again at reasonable prices might have SOME flaw. Just saying.