Not to much compared to you, maybe around $100.
In my case it's not an one session, but it's one bet because I want to try "go big or go home", unfortunately the result is go home and I feel so bad at that time. I think each gambler had suffer a big lose at least once time in his whole life.
If a gambler says he's never lost money gambling in his life, I'd say he's either gambled only once lor he's lying. No matter how experienced a gambler is in gambling, he will lose his money at least once in his life. Many times it is seen that the discussions about gambling are all fine but unexpected things happen in the middle. I bet quite cautiously on different sports and mostly I bet on the team which has the best chance of winning but sometimes there are many weaker teams beating stronger teams than them but here our experience does not help but here fate is working against us. So agreeing with you, I can say this much that every gambler has lost money by gambling at least once in his life.