The GTX 460 - back then in 2010, that was the full mid-range Fermi 104 chip - retailed for $229.
More recently, the GTX 970, a cut down Maxwell 104 of similar size, retailed for $329.
The GTX 1070, $499.
And now the RTX 1070, for $599.
True enough, the price of the milimiter squared has gone up for computer chips with die shrinks. But they haven't gone up like a bubble. Neither have Nvidia's R&D expenses.
Welcome to Nvidia's GeForce Milking Celebration.