Not sure if this classifies as a bargain because you need to put in your details and vote, but you get a free mp3 download of your choice at https://www.trackitdown.net/ after you vote on the DJ Mag Top 100 (http://www.top100djs.net/).
One per email/IP address, and voting closes 23rd September :)
(Has genres of House, Electro, Trance, Techno etc.)