Yu're right about the 3GB 660Ti versions... they're a rare beast to lay hands on, at a reasonable price...
I got two MSI GTX660Ti TF OC 3GD5 in SLI... it's a definite game-changer for DCS...
But I got one (MSI refurbished) smuggled from US Amazon into Europe for 230$ and the other I managed to find a guy who had already bought a new card and suddenly got this baby as a replacement for a year long RMA... got it for 250$, so I can say I had a lucky stroke acquiring my SLI... :D