in the USA it’s been possible to get COL down to sub $50k for a comfortable life and live on 3 mos a year of freelancing mainstream stack stuff, you can focus on long term research indefinitely without distractions. Main downside is can’t live in SF/NY so your project better work out. if you weren’t gonna chase money anyway then what difference does it make?
And yet here i am spending 25k / year on childcare for one kid, not including another (now in public school). Two of them = 40-50k/year. And this is one of the cheapest child cares in the area.