GTX Titans are off casts from the bad Tesla K20X dies from the Oakridge supercomputer. A K20X goes for $3000+ which is why Titans are so expensive even if they are binned dies, are so expensive.
GTX 700 GPUs are the same architecture as GTX 600, GTX 770 is a slightly higher clocked version of the GTX 680 and on the same node so being slightly faster is to be expected. Don't worry Maxwell is coming next year and that will offer much better performance and new features.
Brigade engine is nice but won't be viable for actual AAA games for many years and will require much more powerful GPUs than anything available today. And fun fact Brigade engine runs twice as fast on a Titan than a GTX 680, even then you would need 2 Titans to get even passable performance on complex scenes at 1080p even with the horrible hacks that the brigade engine uses just to be able to run on todays hardware.
@TheVoxelman on twitter
