$20. A friend won $7 million dollars a number of years ago. The guy in front of him at the newsagent mistakenly bought two tickets, but only wanted one. My mate was behind him and got the second ticket which was the winner. Lucky him! We had a good NYE party on his expense though!
Never won a dime, never bought a ticket. I guess that means my winning percentage is 100%? I have never even put even a dollar in a Las Vegas slot either so maybe I am an outlier. Just the idea of dumping hard earned money down a hole like that in the most likely vain hope that you will strike it rich seems stupid to me. If very many people went home from Las Vegas with more money than they came with they couldn't afford to keep all those lights on, could they?
You are only slightly more likely, statistically, to win the Powerball in the US if you buy a ticket than if you don't. My proof is in one of the recent Powerballs where an office pooled their money and bought tickets. They won, but there was a woman in the office who hadn't been working long and didn't have the money to put in for the tickets. Her coworkers decided to include her in the winnings anyway. You could also find the winning ticket on the ground. So I don't buy tickets.
Also, you are more likely to die in a car accident on the way to buy a Powerball ticket than you are to win the Powerball.