Haha, I don't know man. I'm sitting at around 7B at level 43.
Funny thing is, I decided to take a break from the game about a year ago and started again in march/april. I had almost no money but 180 Tokens when I came back. So I needed to buy money from my tokens to buy good players. And in six month I collected 7B, it just comes in with prize money, selling youth players, tickets and so on.