Many people want to be the first to use a shiny new piece of software, which could explain why one person tried to sell an early build of Windows 8.
An auction appeared on eBay offering a “real Windows 8 Milestone 3 leaked CD (opens in new tab).” It's unknown if this disc was an official Microsoft pressing, but copies of Windows 8 Milestone 3 have been available off file sharing sites for some time now.
The auction has likely since caught the attention of Microsoft, which probably explains why the listing was pulled. According to WinRumors, the auction listing had a price of $1,500.
For those who really want to try out Windows 8, but to abide by Microsoft's rules, there's been rumors that Microsoft will release a beta at its BUILD conference this September. We'll know for sure in a couple of months!