Harvard's tuition back then adjusted for inflation is around $18,700. Assuming 10 classes a year an using an average class size of 40 students (which is what Harvard reports), that's a budget of $74,800 per class. You should be able to run a college on that, even taking into account some overhead for libraries and such. Yet Harvard today charges more than twice that.
The issue is, after the most endowed schools ($/student), there is a steep drop where schools suddenly aren't able to provide the same opportunities for their low-income students, but still compete for students capable of paying in full. This leads to escalating costs, as schools construct nicer gyms, study areas and dorms, pricing out the mid-to-low income students.
Furthermore, you are letting them completely off the hook for exploding expenses. Check out the administrator to student ratio changes from 1960 to today. College payrolls are now stuffed to the gills with deanlings and deanlets with no educational purpose whatsoever.
http://ofr.harvard.edu/site/policies-issues/financial-aid/
So that seems to me to say that if a family is in the bottom half of average household income, Harvard is free.
I just don't think we should be using Harvard as an example of the high cost of a college education when it seems to me that they are committed to making it affordable for their students.
So if you work 15 hours/week during the year and 40/week during the summer and take the winter break completely off that would be 40 * 4 * 3 + 15 * 4 * 8 = 1140 hours. If you manage to bring in $2.00/hr that would be enough to pay your way at Harvard.
That sounds doable for a person who isn't a genius and willing to sleep only three hours a night or otherwise make really big sacrifices. Truly exceptional people will always be able to bootstrap. But one thing I think is important is to make it possible for those who are talented but not insanely talented (I don't know what the percentages are) to get a degree and learn enough to be useful to society. It's remarkable that people really could (at least in some cases) do that without going into debt.