I think nvidia is price performance competitive pretty well up and down the latter right now.
I disagree, the 770 2GB is a joke at the end of 2013. The 4GB is $380 and offers basically nothing over the 280x @ $300.
The 290 is coming, it will probably make the 780's value overpriced too. It's closer to what it should be, but I'm not sure it's cheap enough. Compared to the reference 290x it's not far off, however the aftermarket 290x's will probably make it less appealing.
Then the titan is absurd (yeah, yeah DP or something

).
The 760 might be a touch overpriced too but I'm not sure since the 7950/70 sales might be dying out and I haven't followed the 270x or whatever that price range cards are.