Ebay. It's starting bid is $300,000. It is located in Festus, Missouri, United States and was initially purchased by the Sleeper family in 2003 on ebay. It has 3 bedrooms, 2 bathrooms and is 2.80 acres. If you want to live in a cave house then start bidding now. I have not seen any bids at the moment though. You can see more about this home for sale through the pictures below.