you have to consider this first before buying
" OEM
A product designed for sale to an equipment manufactuer (Doh!), usually comes without a fancy box, software often has to be downloaded. Support and warranty can differ from the retail version as well. Very rarely an OEM version of a card can be clocked slower, have a different BIOS or have reduced specs/features.
Check carefully, compare all specs to the full "retail" version of the card, and if you are lucky the only difference will be missing out on some bundled games or a driver cd that is outdated anyway."
you have to see for how many years did he use it and check the card with benchmarks before buying.