Elon Musk
While he's no doubt in the process of planning his space mansion on Mars, Elon Musk has seriously downsized his real estate portfolio here on Earth. After declaring that he'd be "selling almost all physical possessions" and "will own no house," the billionaire offloaded nearly all of his seven properties and has reportedly moved into a $50,000, 375-square-foot "box home" in Boca Chica, Texas.