After 2 months of posting this, the 280X still seems like a much better alternative to the S7, even though the S7 is about $500 now instead of $800.
The 280X makes only 70% from what it made back in Feb 10th, so I guess after the huge pump and huge difficulty increase, its still pretty impressive.
It was good already having some 280x and buying some 7950/280x or such at 140~, but now i been buying strictly retail low TDP cards, with better W/MH than Nvidia and r9 2XX AND much much better MH/$ than Nvidia, though not as good as used GPUs (i guess, but who knows people are still buying like crazy even when retail would be betteR).
I'm disappointed that Nvidia have no place in Ethereum, the prices of 970 just doesnt meet the performance. But once you move away from Eth, maybe you can go to a coin that is OpenCUDA friendly?