I've sold a bunch of great video cards (and other stuff) at fair prices to a number of happy buyers, and I've bought quite a bit of good stuff from honest sellers on eBay as well. Like any sort of marketplace where you can buy used stuff, you have to know the products that you're buying, and you have to use a little bit of common sense. You can buy game codes on ebay, just make sure they are something like a voucher from AMD Never Settle promo (or NV equivalent), and you'll be fine. And NVIDIA Surround lets you game on three monitors from a single GPU. New FXAA and TXAA modes eliminate jaggies. GPU Boost dynamically boosts clock speed for extra performance. I should have (and did) know better, but I got greedy. The GeForce GTX 680 is the fastest and most power efficient GPU weve ever built. The seller actually refunded my money on the spot when confronted, but I did have wrestle with Valve a bit to get my Steam account back. If you are using an NVIDIA graphic card, we suggest using NiceHash QuickMiner. Yep, it turned out being a gift purchased with a stolen cc.
However, after filing a dispute I got all my money back, and eBay closed the seller's account. The price was 'too good to be true', and that turned out being the case.
One was a brand new mac mini from seller that had sold 100s of them with positive feedback, but turned out to be selling them before he actually had them in stock. I should also mention that in both situations, I sort of knew I was taking a risk. To be fair, I have dealt with scammers too, but I've never lost a dime in over 12 years.