I don't know whereabouts he lives, but where I live the GTX 760 is only about $20 more than an R9 270, and it certainly warrants that price. Out of curiosity, Sithex, what PSU do you have?
A GTX 760 would require 2x 6-pin connectors, an R9 270 would require 1x 6-pin connector, and a GTX 670 and R9 280 would both require a 6-pin and an 8-pin.