I have a brand new GTX 760, receipt included from Novatech. I'm selling it for £130.
I had two of these cards running SLI, however, the original card suffered some fan blade damage, so I sent it back to Novatech, who offered a straight replacement for a new card, which I'm selling now. While Novatech were deciding what to do, I decided to upgrade to a 780, so now I have no need for the card. The box is not sealed, however the anti-static bag still has the seal intact and is un-tampered.
I have a second GTX 760, which I can also sell, but this has been used with some scuffing on a small heat sink plate underneath, this one is from ebuyer, but is older and will sell for £110.
I can provide pictures of both cards, including the receipts if anyone is interested.
