What a pleasant fantasy to indulge in…
While I can appreciate your desire to buy the island, who do you think will sell its sovereignty? The days of buying, say, Manhattan Island from unsuspecting natives – who didn’t quite comprehend the finality of selling sovereign title in the way that Europeans did – Europeans who could then enforce their title with steel and guns – well those days are over for now.
Who do you propose in your band of back-to-nature campers will mount the coast guard, navy, army, and air force necessary to maintain your independence? (An air force especially, because without air superiority over whatever invaders plan to take your island back – for example, the tax collectors from the country who won’t recognize your secession – none of the other defense forces will matter much. And then the band of guerrillas you plan to mount a Peter Pan insurgency in the hills and forests will be summarily wiped out by trained, disciplined and well-led ground forces who don’t share your desire to “go native”, but just want to wipe out your troublesome band and get back home to their televisions and air conditioning. The coast guard, navy and army will be required to protect the air base. Or do you suppose you can contract out that work?)
So be sure to save some funds in your island purchase price for the well defended air strip (because your air force needs a place to take off from, to refuel and maintain the hardware, after all) and the planes, and the fuel, and the ongoing training and patrols and so forth. A hundred, you say?
Hmm… good luck with that.
Private islands are no trick if you have the money. Your title will be defended by the host country – as long as you recognize the host country’s sovereignty over the island and pay the taxes or whatever else is required to support the host country. Whether I like it or not or whether you recognize it or not, “independence”, at least for now, is an elusive dream. Maybe when that dream is realized, you’ll wish it hadn’t been, too, because when that day comes anyone who wants the island more than you do – “payment” be damned – and has a better strategy and the necessary force to take it from you, will do so to establish their idea of utopia.