Gam3r01 :
Different recording software, and processors were used. So you cant base assumptions off of that.
The 780Ti is the fastest single GPU card on the market, so the 280X lags behind.
As for the price, 760 or 770.
Wow, the excuses never cease, but they are running out. Even in the face of real world evidence, some refuse to come to grips with a $300 card keeping up with a $700 card in BF4. That after months of ridicule of Mantle by even an admin that banned me for a short time when I'd had enough of his constant bloviating.
In the video above he used an i7 980, hardly a slug. I used Action! to record the game which is no better than Shadowplay as far as FPS hit; I don't think either lose a lot. Mantle cannot be recorded in Full Screen mode.
Here's a GTX 770 1080p Ultra on Altai Range
http://www.youtube.com/watch?v=04JE311zaO0
FPS
Min: 47
Max: 132
Avg: 59
R280x 1080p Ultra Mantle
http://www.youtube.com/watch?v=XM0vcvb7OyY&feature=youtube_gdata_player
No smoothing or cropping; just the raw data, full round. 78 FPS avg
With smoothing, the average varies little which means the lows and highs are outliers, still 78 FPS avg.
78 FPS vs 59 FPS, "only" 25%
Prices for the 280x have come down close to what they were before the gpu mining fad ruined their value (bang for the buck).
BTW, you forgot to mention the 295x2 being the fastest single slot gpu.