the 560ti is still a pretty decent card but since the 7850 does provide better performance, i really wouldn't suggest buying one for more than $160.
here is a black friday deal on the egg:EVGA 01G-P3-1561-AR GeForce GTX 560 Ti FPB $179.99
Save: $60.00 (25%)
$149.99 after $30.00 rebate card
or you can look at a 7870 until the prices go back up:SAPPHIRE Radeon HD 7870 GHz Edition OC 2GB $209.99
Save: $40.00 (16%)
$194.99 after $15.00 rebate card
the 660 mentioned above is also a great choice.