Regarding the VRAM stuff, this was posted @ overclockers a few days ago:
I'm personally going to use my GTX 970 SLI setup until the 16nm Nvida GPUs arrive (hopefully in 2016) so I hope 4GB is enough until then.Press announcement!
I spoke to NVIDIA yesterday, they are saying there will be no 8GB cards and that GDDR5 is in shortage and that they can't handle 4GB 980 and 970 demand, so no 8GB's.
But that was yesterday, so I will ask again tomorrow.
But my pricing is my own promotions and it is just Inno3D, other cards will be the same, plus if NVIDIA do this the price will be very high for the priviledge and Etailors will mark up massively as 8GB cards will be even more short than 4GB versions were.
You have to remember for every one 8GB 980, NVIDIA can sell two 4GB 980's and they focus on GPU sales, not memory sales, this is why 6GB 780 was never available so well.
If it comes and I hope it does they will be very expensive!