Ivy fees are pro-rated by income. Last I know of, around 2010, an Ivy my kid was at was tuition free under 75K family income per year. I was low middle income, then, and we were under that.
Lots of grants available, as well, because of endowments. My kid came out with c. 10K debt over 4 years. STEM grad. Could always find work with the school when in session and always worked summers elsewhere. 1st year salary, after advanced schooling, was obscene. ROI is enormous.
For the most part, the hardest thing about Ivies is getting in. They take care of their students. Good grades, good SATs, good interview necessary and it helps to have a talent, such as a sport, music, math aptitude, etc. Nothing beats a coach or professor walking your application into the admissions office.