You can get a SAGER 8170 or 8150 for that price with same spec as the MSI but with ATI 6990M GPU which is like the 2nd best mobile GPU. if you pay slightly high you can even grab a 560M SLI in the 8180 model.
But the GT683DXR with GTX570M is worth the for that price for build quality, brand value and of-course the colours on the side. Mind you that this model do not have a backlit keyboard though. The bigger GT780DXR has the backlit steelseries keyboard.
if you're looking to buy a new laptop I would not do it on ebay
There are online stores like newegg, tigerdirect, etc. Or from online resellers like xoticpc, gentechpc, originpc, malibal, etc. Head over to forums at notebookreview.com, you will find a lot of information.