Depends on the amount of change you mean. $50k would contribute to some good changes, while $5000000 would completely change my circumstances.

(Mine’s in US dollars and I assume this is after taxes, etc.)

Don’t get me wrong, I would be happy to win any amount of free money even a few dollars is a few dollars more than I have now. A couple thousand dollars would be amazing, but I think it would take about $30,000 (pay off car loan) to actually make a difference in my day-to-day life. And I’d say at least $200,000 (pay off a larger loan) to make a big difference. Probably about $1,000,000 to pay off all my loans and make an actual change to how I live my life.

Every buck changes

$25k to give a big boost. $500k to set my business up so well I could work less.

I'm not going to do the math (if anyone from r/TheyDidTheMath wants to give it a shot?), but whatever amount I can invest in a "risk free" investment (t-bonds and such) where the return percentage is basically guaranteed, and where the interest amount generated on the principal is enough to cover whatever monthly expenses I have 4 times over into perpetuity, without detracting from the principal.