After facing allegations of workplace misconduct, Carolina Panthers owner Jerry Richardson announced he was selling his NFL team. Whoever buys it will be the owner of a franchise valued at $2.3 billion and one that earns $385 million in annual revenue.NFL owners have to possess a certain temperament to be successful: Major connections, business savvy, shrewd business skills and, of course, a whole lot of money. It's not all fun, games and big payoffs.Click through to find out what it takes to join the tiny group of elite business people who own the most valuable sports franchises in the United States.