I track the EV of 5 different lotteries available in Minnesota. At this moment only one of them is over 0.5, at 0.55. I don't even think about buying a ticket until it gets over 0.8.
I'm not sure that is really logical. The odds of winning are the same regardless of if it $400m you can win or $20m. However, the effect on your life would be basically the same in either case.
To be fair, I do much the same thing. But, it doesn't really have a basis in logic. It's all psychological.
