Little-known facts about Bill Gates' $124 million mansion

Someone once paid $35,000 just to tour it.

Microsoft holds an auction each year, where employees donate products and services to be bid on. Proceeds go to the company's charitable fund.

Gates has donated private tours of Xanadu 2.0 in the past. According to the Puget Sound Business Journal, a Microsoft employee once won the tour with a bid of $35,000.