Gtx 760's and 770's

so I'm wondering if the price difference is worth it to step up from a GTX 760 sli configuration to a Gtx 770 sli configuration on a 60hz monitor. I want my computer to be usable on ultra settings for a long time on any game and i don't know if the difference in Sli performance is worth it. I am not sure if a single 780 or 780 ti would be a better choice when power draw is no concern. I really want to know if any of these card configurations would be usable for 3+ years. I don't know if a difference of $100-140 would add another year of good performance or if i would be better off just going for a lower level set of cards all together.

770s will out perform the 760s any day. The 780 ti is a sexy beast of a card that will be able to handle  everything you through at it, same as the 780/

 

Now price wise..

the 760 will range from 260 - 320... 2 of them 520 to 640 

the 770 will range from 320 to 440.. so 2 of them will be 640 - 880 

780 is 500 

780 ti is 700 

so its really up to your budget. 

 

760s and 770s should out perform a 780 and 780 ti with 2 cards.

I'm looking as black friday deals and cyer monday deals so price into as huge but i don't know if the difference would be in performance would be at 60hz