Newegg is selling Galaxy GTX 460 (Fermi) GC 768MB for $130 - 50 rebate + $8 S/H. Limit 2 rebates per product; so you can have a decent SLI for about $170 (shipping is $11 for 2). This may not be the most current hardware, but it does support DX11, and as SLI it can put up a good fight against GTX480/570 (a GTX460 1gb SLI can definitely surpass a single 480). Personally, I am not a fan of Galaxy's aesthetics, but this cooler is supposed to be fairly quiet and effective. I've never had issues with Galaxy's rebate, either.
http://www.newegg.com/Product/Produc...82E16814162058
http://www.newegg.com/Product/Produc...82E16814162058