In early 2007, reports began circulating that some extremely rich person had commissioned a private variant of Airbus' then-newly introduced A380 airliner, at a starting cost of $300M. The double-decker jumbo jet—still the world's largest passenger jet—can accomodate 853 passengers in commercial guise, but the buyer, who was later revealed as Saudi Arabian royal Prince Al-Waleed bin Talal, was said to have spent an additional $100M to $150M to outfit the plane to his high standards and transport no more than 100 people. But now the prince has apparently sold the plane before it ever took flight, to an unnamed billionaire desperate to skip the waiting list for the world's largest private jet.

? Prince Al-Waleed tapped interior designer Edése Doret—a private jet and megayacht specialist—to transform the interiors into an airborne palace. That process started simply, at least by these standards. Doret designed a 14-seat dining table for the Prince and his guests, complete with cushy chromed chairs and a glass chandelier, all rendered in soothing neutral tones.

? Adjacent to the dining area, a lounge area boasting three sofas, a pair of chairs, a shiny coffee table, and four rather hideous light fixtures. As if guests weren't impressed enough already by a half-billion dollar private jet, there's an illuminated nook in the divider to hold a scale model of the owner's absurdly large motor yacht. A huge flatscreen television, mounted on the wall opposite the ship model, provides more pedestrian entertainment.

? If the upgrades mentioned so far seem banal by private jet standards—and/or hardly worth $150M—this is where things get crazy. According to the Sydney Morning Herald, the record-breaking jet will have the world's first elevator in the sky, providing access to the plane's three levels in flight, as well as extending all the way down to the tarmac when parked, for easy VIP egress.

? Doret had been planning to include a whirlpool tub in the design—one with "a rapid drainage system that can empty the standing water in seconds to a tank in the cargo hold"—but Airbus refused to include a swimming pool on board. What is reportedly making the cut is a special "magic carpet" room on the lowest level, which is outfitted with a transparent floor, providing astounding views of the countryside from cruising altitude.

· One 'World's Biggest Jet,' Please [WSJ]

· Prince Alwaleed sells A380 flying palace [Arabian Business]

· Flying Palace [Sydney Morning Herald]

· Aviation [Edese Doret]

· Airbus Says No to Prince's Swimming Pool at 35,000 Feet [The Life of Luxury]