I think they have such a good understanding of investments and assets. They have wineries, and rice products and loads of antique art. And most of them seem to get educations and actually WORK to earn even more money. They're not just living off the kit (although I believe I read the Princes receive an allowance?). They have money but also an extremely high work ethic and drive to succeed.
Für Gott, Fürst und Vaterland
"It is a truth universally acknowledged, that a single man in possession of a good fortune, must be in want of a wife" Pride and Prejudice