You would have a point if they didn't increase performance to match the increase power consumption. Now ATI might not have managed that but NVIDIA did.2) Its not only expensive from a transistor PoV. Its expensive from a power point of view. The HD2900XT and 8800GTX cards ((yes the 8800GTX is fairly power efficient. But its still enough to heat up a room))
The problem is that you can't limit yourself in your purchases not that their architecture uses too much power.