Decided to buy this game after reading couple of reviews, seem like a fun game.
Found this website to be the cheapest and most importantly it allows you to pay in Australian Dollar via PayPal.
Not like other websites that requires you to pay in Euro or USD etc.
I bought it myself and it literally take me less than 15 minutes to receive the game (from creating new account to start downloading it via Steam).
I even talked to Live Chat Rep who confirmed stock and inform me that they have sent the code to my email (which I found it in spam mail).
They also have some other weekly deals like: Metro:Last Night; Remember Me; Bio Shock: Infinite; Borderland 2; ARMA II etc. But not sure if they are cheapest.
When you redeemed the code on Steam, what did it say for the game's version? eg: "GRID 2 Retail", "GRID 2 ROW", "GRID 2 RU" etc