Honestly, this is an absolute steal at this price, and having played it, i would of spent full price on it aswell. This is a game not to be ignored. Absolutely perfect balance of combat/stealth and upgrading elements to satisfy most, however i cant stress enough to play this on the hardest difficulty to get the most satisfaction out of it. The "missing link" dlc that can be picked up is definitly worth the extra cash aswell, giving about 5 hours more of gameplay and alot of great features.
In short, if you are not sure, or on the fence on whether to pick this up, do not hesitate, GET IT!