The other reply has clarified that state schools don't cost that much. But just to add on, a lot of international students are merely upper-middle class in their own countries (i.e. family has 1 non-luxury car, lives in a 2 bedroom apartment, takes 1 international vacation every 3-5 years). They take out student loans just like American students and count on paid internships and post-completion Optional Practical Training jobs to pay off those loans. While they're studying they tend to live very frugally - no cars, very little eating out or partying, sharing rooms etc.