The i5 is around 80$ cheaper and the 670gtx is around 90$ more.
You also could save some money by buying a motherboard from ASrock (Z77 Pro3 or Pro4).
I got the Z77 Pro3, one of the cheapest Z77 boards and its perfectly stable.
And its powerfull enough to overclock my i5 to 4.5Ghz wich is a good result for a Ivy Bridge CPU.