You will need ~$650 bucks to match next gen consoles on PC

[disolitude]

Here is an article for those that think you will run out of VRAM before you run out of gpu juice...

http://www.anandtech.com/show/5805/nvidia-geforce-gtx-690-review-ultra-expensive-ultra-rare-ultra-fast/11

"Battlefield 3 has been NVIDIA’s crown jewel; a widely played multiplayer game with a clear lead for NVIDIA hardware. And with multi-GPU thrown into the picture that doesn’t change, leading to the GTX 690 once again taking a very clear lead here over the 7970CF at all resolutions. With that said, we see something very interesting at 5760, with NVIDIA’s lead shrinking by quite a bit. What was a 21% lead at 2560 is only a 10% at 5760. So far we haven’t seen any strong evidence of NVIDIA being VRAM limited with only 2GB of VRAM and while this isn’t strong evidence that the situation has changed is does warrant consideration. If anything is going to be VRAM limited after all it’s BF3."

So let's recap...
BF3 on high settings, 3x 1080p resolution, 680SLI (3x more powerful than ps4 gpu)...no VRAM bottleneck with 2gb.