I don't know if anyone already posted, but Newegg is having a Labor Day sale on Squeenix and 2K titles.
Only thing that's kind of noteworthy as far as I can tell is Supreme Commander 2's DLC being 75% off. It's even cheaper with the code LABORPCDD16.
Knocks it down to $1.06, probably as cheap as it's gonna get outside of a strange Humble Bundle. As for whether or not you should get it, it adds a ton of stuff to the game and the consensus is it's a must if you plan on ever playing the game. Planning on ever playing the game being the key phrase there.
Also, Bioshock Trilogy is pretty cheap if for some reason you don't have that. Keep in mind the free upgrade coming along soon.