It is very difficult to know who owns the most expensive private jet. Jets are bought and sold constantly and depreciate over time, so they will likely decrease in value as time goes on. Many billionaires can be opaque about their luxury jets and lavish lifestyles. While the most expensive jets intended for a particular individual are likely Air Force One's new Boeing 747-8s, these are not privately owned (the US Air Force owns them). The most expensive non-sanctioned private jet might be a Boeing 787-8 Dreamliner.