Why I don't see the PS4 and the X1 going below $300 price tag for a long time

[Scoobes]

Surely there will be ways around this? It's what engineers do, right? They hit a brick wall, then invent a bulldozer.

How's research into 3D integrated circuits going? Couldn't this be a possible way around the problem of costs not decreasing significantly with further die shrinks?