Sure, once you start dividing students into subclasses, you are going to get different answers for different subclasses. Even if you are just talking about a college, research grants, say, are typically earmarked, and may mean a lot to some students, very little to others.
On this specific issue, I note Princeton reported:
Of the $219 million in net total tuition, fees, and auxiliary revenue recognized in fiscal year 2022, $188 million was from undergraduate students, $22 million was from graduate students, and $9 million was from other sources.
I think this reflects a general truism–outside of the sorts of professional schools Princeton doesn’t have, net tuition at these elite private colleges mostly comes from undergrads. Most grads expect to get funding.
Harvard then had a fun chart breaking it down by unit. Law was 47% gifts, 45% net tuition, 3% research, 5% other. Faculty of Arts & Sciences (which I assume includes grad students, although I again suspect the college students would dominate the net tuition in this category) was 59% gifts, 22% net tuition, 13% research, 6% other. Engineering & Applied Sciences was 38% research grants, 38% gifts, 21% other, and 3% net tuition. So basically, FAS was somewhere in the middle between the “extremes” of law and tech in the biggest categories.
OK, so no surprise here–tech stuff at Harvard looks at least more like MIT. FAS stuff at Harvard at least looks more like Princeton. Law is more tuition driven than any of those (although still gets a lot of gift support).
But I am not sure this is motivating a change in understanding the incentives, other than just adding nuance. Harvard does do tech stuff, and research grants are important to supporting tech stuff, not so much net tuition. Harvard also does professional stuff, and that balance may reverse in those cases. But it also does a lot of non-tech, non-professional stuff, and net tuition falls in between in those cases. And in all cases, gifts are big for Harvard, but bigger in professional than tech, and even bigger in non-tech/non-professional.