I really cant remember when last I bought a new piece of hardware. As far as graphics cards go I normally just go for EVGA due to their "guest warranty" program.
As far as buying second hand, just make sure you buy from a reputable seller, pay via paypal (non gift) if possible and find out about any remaining warranty..
As far as buying second hand, just make sure you buy from a reputable seller, pay via paypal (non gift) if possible and find out about any remaining warranty..