SLI or new card? What's better?

Question

Iron

i5-3470 in use,
gtx 660 ti sli of 3 video cards (purchased for Avito ~ 15k) or a new card of the higher series at about the same price?

Answer 1

Do not forget that all this happiness also needs to be nourished. Those. You can't get by with an average power supply.
One new one is better. And then buy more if needed.

Answer 2

for games, one top one is better.