i wanna buy an island and stay on that island until i was bored

and then move to another island

A million dollars doesn't get you an island. It gets you a decent house were I live xD
it could get you a small island in a remote place of the world.
It would cost you more on fuel than the actual island xD. I can't think of an island small enough to have a house and electricity and everything, but not cost more than several million.