How Do You Study Abroad?

I'm curious about studying abroad. I'm from the province and have only ever planned of going to Manila for bigger opportunities. Manila itself is already expensive, I wonder why people would rather go to another country just to study? Isn't it going to cost you more than just studying at a university or educational institution situated in a region where you live or work?

How do you even manage to keep your jobs if you fly to another country to take up master's and PhDs? Do you just quit or find work online?

What is it that I don't get that people just make studying abroad workout for them? Is studying abroad only for the rich?