This is point-blank wrong, unless you're only talking about elite private schools. Most state schools cost around 1-1.5 years of full-time salary, discounting room and board since you have to pay for somewhere to live independently of if you attend university. If your goal is to simply get a degree, you can do it for less than $50k (which is definitely still off compared to the 70s, I agree).
In return, you go to school, which one hopes is worth the cost over the course of the rest of your life, however you measure it (but here, mostly in currency). Which brings us back to this discussion.
However, to include college time in the opportunity cost, it would need to be 'for all', not 'there exists'.
Source: myself and literally every single college person I know who attended public universities in the Midwest
But to have almost zero debt is worth it. More people should consider it.