Using a private jet isn’t so much about luxury as saving time and this is why the people whose time is worth the most are the ones that use private jets most. It is CEOs and executives and company’s top people who fly in private jets most of the time, not people flying places for pleasure. It is much easier to justify the cost of running a private jet or chartering private jets when you can quantify the value in terms of the value of time saved for a certain person. If you aren’t based near a major international airport then you can save time with a chartered flight by being able to go to a local regional airport or even a local airfield and then fly to wherever you want with no connections or changes of plane; direct from Tucson to Grenoble isn’t a problem with a private jet, though some may need refueling stops. Even with refueling stops the time spent undisturbed inside a plane is time saved, you can work or relax whatever you need to do, either way it will save you time once you arrive. It may be that you are crossing time zones ands will be going straight into a meeting and with a private jet you can have some real decent sleep in private and undisturbed.