MO Jews tend to be pretty well-off because they choose high-paying professions. They tend to choose high paying professions because they know tuition and housing are expensive. Becoming MO won’t make you wealthy if you’ve already chosen your profession.
It’s supposed to be a lot easier to be MO is Israel, because tuition is so much less. But there are fairly affordable MO areas in the US outside of the big ones — I think Cleveland, Buffalo, Detroit and Memphis might be examples.