I have just noticed it on Steam's top seller list for $14.39 and decided to check GMG and found that you could use the QRJ1I6-2SSDU0-LN9UUG code to bring its price down to $12.24.
Please note that this is a preorder and the game will be released on 9 October 2014. I can't comment on the quality of the game as I have never owned a PS3, but I'm psyched to play it on PC.
The more patient OZbargainers could probably wait until Steam's Christmas Sales as it would probably be discounted heavier by then.
Also, check out the referral link below for additional $2 instore credit if you don't have an account yet.
Am I doing something wrong? After I added the voucher code, it returns "Unable to add the voucher"…