Paul Allen – Allan Island, $13.5 Million
Contrary to popular belief, Paul Allen did not rename this island after himself. It was, in fact, given that name in 1841, named after William Henry Allan, an American Naval Officer during the War of 1812. Allen splashed $13.5 million to buy the island in 1993, but never developed it, turning his attention to another property he owned on the San Juan Islands off the US coast.
It remains undeveloped, with nothing but a grass airstrip and caretaker quarters on it. Allen, who co-founded Microsoft, eventually sold Allan Island for $8 million in 2013 and sadly passed away in 2018 at the age of 65.
