Warlock : Master of the Arcane cheap at Green Man Gaming

[Arctic Blast]

Since it uses a Steam key, you don't need to use the GMG client (which is godawful). Just plug it in to your Steam client and get in on a great game.

Game is $4.99. DLC is also 75% off, but they've sold out of keys for 2 of them.

http://www.greenmangaming.com/hot-deals/

Bottom of that page.