Ball you should just take a break. If GTX470 is the superior card to the 7850, then why did NV bother refreshing it with GTX560Ti and upped its performance with GTX570? GTX470 is amazing value for $40 but what if the OP isn't interested in buying it used, or can't find it for $40? I still think it's not really applicable in this case to compare used cards vs. new cards. It doesn't really serve a lot of purpose since 470 isn't a card one can buy on Newegg right now.
470 isn't superior, it just represents a better initial value, a comparable option as you were.
That is all.
Why is AMD falling flat on it's face unable to move many of these 7970s that we both agree are better than 670/680s, yet those are selling in droves. Droves, so many Nvidia didn't even bother with cut down cards because they simply didn't have the fab capacity to add more cards when they couldn't keep their high end cards in stock. Remember Nvidia is trying to make three cards out of a GF104, imagine that, a GTX 460 at the top, competing with AMD's top card. Then having to cut it down two times just to compete with $400 and $350 cards... Please generation jokes on us.
Why was the 680 and it's awful overclocking met with rave reviews by sites?
It's still a good value at $100, doesn't need to be $40. $100 is very easy to find, lower is possible as well.
GF100 was bad out of the gate, but what happens as you go along? Refinements? Yes please, you think I can run stock at 33% fan under 98C because my cards are the same as the inital review samples? Do you think I'm hitting 900 core on reference air with a card that was hitting 103C at stock with nearly topped out fan speed in reviews? You think there might be a difference between the cards people have now and the cards that first came out? Maybe? Possibly? A difference?
It's not for you or anyone but the OP to say if used is not appropriate or an option.