Pop stars dominate this years Forbes Top Earning Celebrities Under 30. Forbe's research is based on their Celebrity 100 list, and do not deduct taxes, and other fees/expenses. 1. Justin Bieber, age 20, $80 million, 2. One Direction, average age 21, $75 million, 3. Taylor … [Read more...] about Pop stars dominate this years Forbes Top Earning Celebrities Under 30