For proof that the topsy-turvy world of private island sales does not function like the rest of the property market, look no further than Ronde, an island in the Caribbean.

With almost 2,000 acres of rolling hills, tropical forests, secluded beaches and a price tag of $100m (£49m), it is being touted as the most expensive private island ever put up for sale. That Ronde has actually been on the market for almost a year, initially at $70m, is not the point. The price rise might be just the ticket for attracting attention in a market where developers of luxury getaways compete to outdo each other.

Ronde lies three miles north of Grenada, and south of St Vincent and the Grenadines, in an area where every other speck of rock is a resort sheltering a celebrity from the lenses of the paparazzi. Here you will find Mustique, Princess Margaret’s favourite hideaway, and now popular with David Bowie, Mick Jagger, Tommy Hilfiger and Elle Macpherson; Canouan, developed by Donald Trump; Petit St Vincent, a more obscure private island resort, popular with yachties; and Palm and Young islands, also loved by the wealthy and world-weary.

Ronde’s price hike seems arbitrary: no agent can claim that the average price of an island has risen by more than 40% in the past year. However, Caribbean property is becoming ever more sought-after, as developers seem unable to build enough holiday havens for the rich and famous. Ronde might not be much at the moment – there is no dwelling and no infrastructure – but its Grenadian owners are emphasising the island’s possibilities.

“The area is on a roll at the moment.

Money is pouring in,” says Cheyenne Morrison, of Coldwell Banker Morrison’s Private Islands, one of the brokers dealing with the sale. “One only has to look at Mustique to see the potential. This is one of the most prestigious island areas in the world.”

Ronde, a three-hour flight from Miami, is just as warm, lovely and well located as its neighbours, but much bigger. There are now 65 villas and two hotels on Mustique’s 1,400 acres, while Necker, Richard Branson’s high-end holiday haunt in the British Virgin Islands, at the other end of the region, is just 74 acres.

Private islands are the ultimate luxury status symbol. Ted Turner, the founder of CNN, owns St Phyllis island, in South Carolina; the Heidsieck champagne family owns Illiec, off the coast of Brittany; the Forbes family has Naushon, off Massachusetts. Part of the allure for high-profile owners is the unrivalled privacy. The late Marlon Brando snapped up Te’tiaroa atoll, near Tahiti, while shooting Mutiny on the Bounty; Agnetha Faltskog, of Abba, bought the forested island of Ekero, near Stockholm; the actors Johnny Depp and Nicolas Cage both own property in the Bahamas; and Ian Fleming, the creator of James Bond, had a hideaway on tiny Goat island, off Tobago.

Even if you don’t have hordes of overzealous fans to escape from, it is easy to fall in love with the idea. If hell is other people, owning a private island must be heaven – and it need not be as expensive as Ronde. You can expect to pay big money for fashionable spots: $20m-$30m will get you a decent Caribbean or South Pacific isle. But if tropical idylls are not your thing, you can spend far less; Canada, for example, has scores of islands costing less than a studio flat in central London.

What you probably won’t be able to do is found your own country. “The only way to do that would be to find an island that nobody has claimed, and those really don’t exist,” Morrison says. “In reality, in some Third World countries, if you buy an island and you have enough money, nobody is going to bother you.”

There can be problems: hurricanes can damage or even wipe out small islands, and they can easily fall prey to thieves, vandals and even pirates. Installing power and water can be tricky, and building costs are much higher, because materials, equipment and labour all have to be brought in.

Anyone with the money to buy Ronde is unlikely to be bothered by such mundane concerns. Given the appetite for luxury in this part of the world, it seems inevitable it will be developed into yet another tropical millionaires’ playground. Only a true billionaire could afford the ultimate indulgence: to build a single house and leave the rest of Ronde to the rare Hawksbill turtles that have made it their home.

Coldwell Banker Islands

cheyenne@coldwellbankerislands.com.au;www.luxuryrealestate.com/islands

00 61 7 4099 3939

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