StackSocial offers the Name Your Own Price Wordpress Theme Bundle for whatever you want to pay. The minimum price is $1.01, which buys you only three of themes; however, if you opt to pay more than the average (at the time of this posting it's $4.05), you'll receive all 15 of the included themes. That's a total savings of $821 off the list price and the best deal we could find for this collection. The fully customizable themes included in this bundle include Bloggap, Legalized, Themetick, Photex, Invisi, Charity+, and more. Deal ends June 25.
Note that 10% of your contribution will be donated to your choice of charity. (Choose from Child's Play, World Wildlife Fund, or Creative Commons.)