Eh - what the heck, ordered one. Priceplunge is one of the available retailers on ebates.com, so that is another indication of their legitimacy. Plus you can get 4% back on this purchase that way - whoo-hoo, 25-33 cents back (depending on how they handle the shipping charge portion)!
I also did a little price comparing. The game is $29.99 new/$24.99 used at Gamestop. At Amazon, you can get it for $14.99 shipped with Prime (though sold by a 3rd party). Amazon Warehouse Deals has it like new for $14.52. So, yeah, $8.28 shipped for a new copy is a pretty good deal.