6850, 5850, GTX 460 or GTX 470?

[The Green Bean]

I'm looking for the best bang for the buck card from my 2500K rig. I'm buying from Pakistan so please don't post links to websites.

These are the prices I've found:

6850 - Rs 18500
5850 - Rs 20990
Sparke GTX 460 Stock - Rs 18500
Calibre GTX 460 (790/3900) - Rs 21500
Sparkle GTX 470 - Rs 23000

There is also a GTX 560ti for 27000 but I don't want to spend that much unless it's really worth it.

I bought the 470. There was only one in stock and...

 

[Castiel]

Calibre 460 will probably be the best bang as it has the arctic cooling heatsink and will allow for massive overclocks.