Yeah most billionaires are billionaires because they own a company worth a lot. So their wealth is to a large part based on "what would they get when they sell the company". Beyonce is herself the "company" but there is no evaluation for how much it is worth to be Beyonce. She can get a lot of very expensive things for free just for beeing herself. And how much could she earn by "selling out"? Wealth estimations just don't make sense at this level

One trip to Dubai would get her to a billion.

By reported wealth of rich people, yeah probably even higher. Don't forget to add some millions for the months since the last estimate too.