The Criminal Mastermind (hereinafter CM) is an in-game achievement that rewards you with a whopping $10,000,000 in-game dollars.
Additionally: The "All in Order" and "Loyalty" achievements, which grant an extra $2,000,000 combined, stack with the "Criminal Mastermind" achievement. As a result, completing them will earn you a total of $12,000,000 in-game dollars. The requirements for these two achievements are the same as for "Criminal Mastermind."