They might apply, but certainly won't attend if they are admitted to Stanford, Yale, etc. The higher the price differential, the more likely people would be willing to take a 'prestige' hit and go to the lower cost school.

Anyone applying from a family making 400k a year (top 2%) would still be sensitive to an 80k vs 240k/year sticker price change.

This would be true for those whose contribution would be capped based on parental earnings/assets, since their effective price would not increase. And it would be true for extremely wealthy folks whose parents can spend $1M on college and not worry about it. But for the marginal applicants who would be paying full freight under the old price but can't easily toss out another $150k/yr on tuition, there would definitely be a drop in application rates.