i think i'm gonna go with a gtx 770 since i can't find a gtx 780 for under 750 USD right now.
I think you might not be looking at the right card. The 780 Ti is about $700-750 but the regular 780 is like $500 http://www.newegg.com/Product/Product.aspx?Item=N82E16814127746
Even my local microcenter/bestbuy have them for $520.
GTX 770 isn't a bad value either (its $330-340 for 280x/680 OC performance which is good).