Location: Skorpios, Greece 
Purchased: $12,500*
Current Value: $100 million*

Talk about a return on investment. Aristotle Onassis, the Greek shipping magnate who was Jackie O’s second husband after J.F.K., paid just $12,500 for Skorpios Island in 1963. Now, the island’s value is at least $100 million.

Onassis might have spent less than $20K, but the improvements he made cost millions. He imported sand and tropical trees to create a paradise. He hosted glamorous parties there. Skorpios, located in the Ionian Sea off the western coast of Greece, became a bit of a playground for the wealthy and powerful. It was purchased by a Russian billionaire heiress in 2013.