<p>I think I’m figuring out at least part of the answer to my question. Until now I only knew our EFC, not how it’s structured generally. Googling around, I see that EFC does not rise linearly with income. At AGI $80K/1 child, it’s 12% of income, and by the ‘top out’ income of $230K, it’s close to 27%. Of course, stupid of me not to assume it’s progressive. At the midpoint income, $115K, EFC is $23.5K, not far from the apparent $20Kish the avg financial packages at these schools imply. Add in effect of having more than one child in school at a time for many families, and the initiatives some of these schools have to eliminate family contribution for incomes below $60K or $80K (which I just read about for the first time today, NOT well informed), and much of the large average package size is explained. I know EFC and CSS determinations are not equivalent and assets, etc. confound, but that gives a baseline for me to at least think about these things. Must be lots of other factors I haven’t considered. </p>