It can't be too close to 970 performance at that price else it'll cannibalize everything above it. So it will probably be around GTX770 performance levels. With 4GB vram, would make a good SLI combo for cheap!
Not necessarily. 660Ti was very close to a 670 for $70-100 less:
NV is enjoying great sales and high profit margins on 970/980. This could explain why releasing a 1280 CUDA core, 4GB 960Ti would have cannibalized some of their 970 sales. Why do that when 970 takes the $275-500 market all to itself? Right now with the AC Unity/FC3/Crew game bundle, a lot of gamers will pay extra for the 970 over the 290/290X as it is. NV is in a perfect position to milk 970/980 for all their worth. Not only that but if you look at places like Canada and Europe, in a lot of those countries the 290/290X series hasn't experience the major price drops that we see in the US. For that reason 970/980 are even more competitive.
Further, NV is selling 960Ti ~ aka 970M in the laptop segment at very high profits. Right now the ASP of GM204 on the desktop and mobile is so high that 960Ti may have hurt NV more than the strategy they implemented for now.