Benzinga and Yahoo Finance LLC may earn commission or revenue on some items through the links below. Billionaire investor Mark Cuban didn't get rich by clipping coupons, but he sure knows the value of stretching a dollar. In his 20s, he was broke, hustling to get his foot in the door—waiting tables, living paycheck to paycheck, and grinding through sales jobs before he sold his first company and never looked back. Now he's a self-made billionaire with more money than most of us will ever see—but he still ...