well on newegg the 200-300 market is
GTX460 1gb, 5870, 6870 (not interested), GTX 560 TI and 5950. Now the GTX4601gb is 200, the 5870 is 220, the GTX 560 is 250 and the 5950 is 260. And vin im not saying your numbers are wrong, but looking at othersites the race looks alot closer.
This for example across a wider range of games shows them alot closer. So the question is when they are considered equals is it really worth the extra 30 dollars? Note physx and nvidia 3d don't matter to me, I don't play anything that will use either, and the few games it trumps the 5870 significantly I have no interest in I tried metro2033 and was bored after 2 hours of game play. Resident Evil same story I couldnt get into the first one.
But CoD:BO I enjoyed and might play through again. I don't dispute your numbers vin as other sites show the same thing, but in games where the GTX 560 TI pulls ahead, there are also games where it struggles to come close and in the long run i call them equals lol. So with them being equal is 30 dollars really worth it