So I still haven't changed my GPU and I still need other information about what better between ATI and NVIDIA.

I got my eyes on ATI Radeon R9 and HD 8000 series for ATI and GTX 780 and GTX 760 series for NVIDIA.
I know, ATI known for it's lower price compare to NVIDIA. NVIDIA known for it's feature (I think)

My spec at the moment
OS : Windows 7 Ultimate
Processor : Intel i7-3770, 3.40Ghz, 3901Mhz, 4 Core, 8 Logical Processor, 64 bit
Installed Physical Memory (RAM) : 4 Gb
GPU (VGA) : NVIDIA GeForce GT 430, 2Gb, for DDR I don't know between DDR 3 or DRR 4 (I think)

If anyone could tell me which one is better, I would appreciate it
For the prices, in every country is different so I need search it up myself.