Owner: Larry Ellison
Purchase price: $500-$600 million
Tech titan Larry Ellison's purchase of 98 percent of Hawaii's sixth largest island - Lanai - is considered among the most expensive in the world.
Ellison - the third richest person in the U.S. and sixth richest in the world according to Forbes - bought Lanai in June from David Murdock, the billionaire behind Dole Foods. The 141 square-mile island is known for its pineapple fields and is home to 3,000 people. Tourists visit the island for its two Four Seasons resorts, golf courses and luxury housing. Oracle co-founder Ellison now owns the two luxury resorts as part of his share of the island, while the remaining two percent is owned by private residents and the local government.
As part of the sale agreement, former owner Murdock retains the right to develop a 200-megawatt wind power project on northwestern Lanai. That has faced stiff resistance from locals concerned about the operation disturbing archeological sites and displacing native birds. Residents have been vocal in their demands that Ellison respect the island's native history and artifacts in his future development plans.