~
All the winners in the OP's example were spending from 30 cents to $50, not big money for anyone living in the West. So, it wasn't a "biggest risk", if you ask me.
This formula, "the more money you can potentially win, the higher the amount you have to put at risk", is true when you are betting on Red/Black in Roulette, but in slots and lottery, it doesn't work like that.
They spent small money, but we know just about money they used for winning.
I think that they spent more money without winning. But you`re right about the risk, if we are talking about the bet. If we can know the chance of such a win for a such sum - the percent will be really scanty.
You mean, they spent more money than the jackpot amount? More than $18 million, or $40 million? I don't think so.
There are a lot of such cases among slot players. When they win, say, $1k, we all know that they have probably lost more than that previously. But with slots or lottery jackpots it's rarely the case. People normally don't have such money.