The Tropico 4 Collector’s Bundle for 39 cents… um… I’m in.
You could literally sell a couple of trading cards to pick up this bundle.
I heard Alikchi spotted this and the word has spread.
Addendum: As noted in the comments, somebody at Steam noticed their mistake and the price has been changed. It was climbing rapidly up the daily best seller list, so it seems like a lot of people got a bargain today.