2. Prince Charles
Prince Charles has a very generous estate to thank for his estimated $1.3/£1 billion net worth, although there is an expiration date attached to the deal that allows him to profit from what is known as the Duchy of Cornwall. Unfortunately for Charles, the estate was established to provide income for the crown prince and when Charles someday moves on to serve as king, the benefits of the estate will be passed along to William, who will someday serve as Prince of Wales.