The main difference between an agent and broker is the number of responsibilities they're able to take on. A broker can do everything an agent can do, but they have the added responsibility of making sure all real estate transactions are lawful, all paperwork is accurately completed and all finances are accounted for.

Suddenly, the idea of buying an island doesn't seem so crazy. Now where to begin? Surprisingly, you can still find a small island in the northern United States or Canada for less than $500,000, but in the Caribbean and South Pacific, even the most modest private island typically costs $1 million or more.

You can find private islands for sale via Private Islands Inc. or Vladi Private Islands, or by contacting a realtor who specializes in big-ticket sales. Additionally, some high-end real estate companies, like Sotheby's International Realty or Christie's International Real Estate, list private islands for sale.

Sampson Cay, The Bahamas John Malone overtook Ted Turner as the biggest private land owner in the U.S. when he amassed 2.2 million acres in 2011. He now currently owns Sampson Cay, in the Exuma chain of islands in the Bahamas. The 31-acre island is home to a resort and marina, which was rebuilt in 2002.