Owning a huge yacht can be very expensive, even by the standards of their billionaire and centa-millionaire owners—and are perhaps the best case for "Rent, Don't Buy"—but, like the relatively plebeian Florida condo, they can be rented out to defray the cost of maintenance. With price tags north of $100M, the five largest yachts available for charter aren't going to come cheap, even when rented by the week. The Nero, a 296-foot yacht that spends summers cruising the Mediterranean and winters in the Caribbean, is available for $531K per week in high seasons. It might only be the world's fifth largest charter yacht, but Nero has space for 12 guests in opulent staterooms, a crew of 21, a swimming pool, a gym, a jacuzzi, and four jet skis for in-port fun.