I think that extremes exist and go to both directions. I have known people who lost their mind when their wages tripled after they started working abroad (e.g. my father started having mistresses when his salary went from 800 euros to 2200 in today’s money). But I have also known millionaires who live very middle class lives, except they travel more and drive better cars.
There’s plenty of countries with cheap insulin, and people there are fine because other treatments for diabetes are cheaper too.