Since there was a post in another thread about the humble bundles that deal with graphics programs. Here is the current one that they posted today:

Humble Software Bundle: Natural & Digital Paint Kit Bundle

Includes: Inspirit, Flame Painter 4, Amberlight 2, Rebelle 3 and a bunch of brush packs, particle systems for Flame Painter 4, a plugin to connect flame painter 4 to Photoshop, Paper sets for Rebelle 3

You have about 20 days from this post to get it if you are interested.