Spend the extra money on the 970. You will thank yourself down the road. It looks like on eBay the 770s are running anywhere from about $225-$275 (US dollars). As a current 970 owner, I would not even hesitate spending more on a 970 even if it required making a few sacrifices to cough up the difference. While the 970 is more than necessary for games at 1080p and the magical 60fps, that likely will change in the next year or two with new games, as it always does. Irrespective of the fact that like the guy above says, Nvidia will continue supporting it with updates for a few more years.