[PC Steam Key] Borderlands 2 $8.74
It's worth mentioning that the Season Pass is also on sale for $9.23 after applying the code.
I personally can't comment about the DLC contents as I have only played the vanilla version, which was pretty good on its own. Someone here might be able to tell you which DLCs to pick.
Also, the code will only apply to one item in your cart. You will need to purchase them separately if you want to apply the 30% off for the base game and DLCs (at least that's how it works the last time I tried to buy more than one item).
As always, if you don't have an account yet, you could use my ref to earn both of us extra $2 instore credit: http://www.greenmangaming.com/?gmgr=katukeci