In the 1970s, when Sir Richard Branson (then simply Richard Branson) went searching for an island that he could use as a getaway for rock stars on his Virgin Records label, he took one look at Necker Island in the British Virgin Islands and fell in love.

In the years that followed, Branson invested millions of dollars and transformed Necker into a world-class exclusive retreat — “a model for those other small, exclusive private island properties to come,” says Janine E. Cifelli, vice president of Sanctuare, a Stamford, Conn.-based company that represents Necker Island.

Now, 30 years after Branson acquired it, the 74-acre island is not only available to rock stars, but also to the rest of the world's rich and famous — and to incentive groups with the budget to pay $46,000 a night.

It's part of an increasing trend that is seeing more exclusive island properties become available for buyouts. In Necker's case, you can bring a group of up to 28 people to the island to be catered to by a staff of more than 50.

The latest celebrity/entrepreneur to jump into the private-island club is magician David Copperfield, who a year ago bought Musha Cay, a small island in the Exuma island chain in the Bahamas. The island is only available for group buyouts of between eight and 24 people, and according to Cifelli, Copperfield is busy “putting his own personal spin on it.”

About 25 miles southeast of Necker Island, just below Tortola, lies Peter Island, the largest private island in the British Virgin Islands. Also available for a complete buyout, it has become increasingly popular as an incentive reward destination. Peter Island covers 1,800 acres, and its resort contains 52 guest rooms and three villa estates, with a 3-to-1 ratio of staff to guests. Guests can enjoy helicopter tours, scuba diving, and golfing on St. Thomas. The price for a complete buyout? $396,500 from November 16 to April 15, and $259,600 the rest of the year, based on a minimum five-night stay. That rate includes meals, airport transfers, and ferry service from Peter Island to Tortola.

Islands that are available for buyout are never easy to get to, which is precisely the point. According to Cifelli, groups booking Necker Island will often fly to San Juan, Puerto Rico, and then on to Tortola, where they board a boat for the 30-minute ride to Necker. “But the experience makes the travel definitely worth it,” she says.