it was much less competitive to get into colleges and fewer kids going and hugely fewer international applications and nationwide applications have gone way up
In the early 80's -- as the effects of the end of the baby boom in 1964 filtered through to declining college age populations -- Columbia was significantly easier to gain admission to than its academic peers, as was Chicago (in part due to perceptions of urban crime); Northwestern, Tufts and Washington University were tier-below safeties for Ivy applicants; anyone who managed to graduate from an elite prep school was guaranteed admission at Berkeley or Ann Arbor (or any other state flagship); Georgetown was viewed as a peer of lesser Ivies; BU and Tulane were fallbacks for the non-academically inclined; dim guys could write their own ticket to formerly women's colleges like Vassar or Skidmore or Conn College; Vanderbilt and Emory were perceived as regional schools (the latter kept alive through Coca-Cola money); Duke was seen as a beacon of educational excellence in the South but still not on a par with the Ivies; NYU was a commuter school; left-leaning colleges like Oberlin and Sarah Lawrence and Clark and even Hampshire were still seen as offering competitive if second-tier degrees; and Northeastern wasn't a school competitive applicants would even think about (think U Mass Boston).
International students were much fewer at the undergrad level - mostly the offspring of foreign elites.
Yield management wasn't a thing (thanks USNWR). If you were qualified, you got in.
And while I'm sure there's good analytical data out there, it seems like the cost of private colleges for those who couldn't qualify for need-based aid could generally be defrayed by a reasonable mix of loans and work-study. Paying for college didn't seem to be a second-mortgage type of hurdle.
Of course, while the costs were cheaper, the dorms were Dickensian, as my father said when he dropped me off.