Toys of the ultra rich: what they cost

Purchase price: $55 million
Annual operating costs: $200,000 and up

This 681-acre Bahamas island boasts an airstrip, a seven-bedroom timber frame main house, and two staff houses.

Maintaining an island like this requires one engineer to run the water and electrical systems and two groundskeepers, at a minimum, said George Damianos, the Sotheby's broker selling it.

Operating costs can exceed a million dollars on islands with bigger homes, said Damianos, especially since everything has to be shipped in.

But despite their high costs, private islands remain popular among ultra-rich clients. "After you have your jet and your yacht, what else is there to get?" asked Damianos. "Your own private island."

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