If you want to own your own island ,you don’t have to be an evil genius with plans to take over the world in order to have your own island – according to market research, the average island buyer is an American man in his fifties with a background in commerce. To get an island of your own, you will inevitably need deep pockets – but not necessarily as deep as you might think.

Living on an island might be a pleasant fantasy, but think carefully before you take the plunge – splendid isolation might suit you for a day or two, but do you want it longer term? Your choice of island will be influenced by your reasons for wanting one. Do you plan to stay there for the odd holiday, half the year or for evermore? A holiday cottage needs just a small island, but if you’re planning a permanent move you’ll want a few acres at least. If you’re planning a project such as a resort, you’ll need at least 10 hectares (25 acres). And if you’re looking for a long-term investment, there are potentially staggering profits. Aristotle Onassis bought the island of Skorpios in Greece for US$10,000 in the 1960s. Today it’s valued at a cool US$100 million.

Choose where in the world you want to be. Broadly speaking, you will pay more for a tropical island than for one in a temperate region such as northern Europe or North America. You’ll also need some form of shelter and accessibility – a safe docking place or even an aircraft landing strip. Then there’s infrastructure – you will need a reliable water supply, a source of energy (possibly solar power), somewhere local to buy provisions, a medical centre within a reasonable distance and some means of communication with the outside world.

Know how much you want to pay – an island is only worth what someone will pay for it, and there is every chance that you are the only one considering an offer. Metre for metre, you may often find that a private island costs quite a lot less than nearby mainland waterfront developments. There are even bargains to be had. Islands in Nova Scotia, for instance, start from around US$30,000. Even Sir Richard Branson’s opening offer for Necker Island (pictured below) was reputedly a rather cheeky US$160,000.

You’re unlikely to find your local estate agents selling islands, so be sure to check the credentials of anyone who presents themselves as an agent. And however busy you may be, never buy an island unseen – you can hardly take it back it if it isn’t what you hoped for.