The Good Guys - 3DS Lego City: Undercover - The Chase Begins $44
I'm not sure why, but my AV (Kaspersky Internet Security) stated this was a phishing site…may just be a false positive. It's TGG after all..
Anyway, this is the lowest I've seen this game for. To compare prices:
EB Games - $69.95
JB Hi-Fi - $59.00
Ozgameshop - $48.99
Game UK - $50.60
Amazon UK - $47.23
All prices do not include shipping.
If you wanna try the game, go to an EB Games store; the 3DS there should have the game.