Money is not the only way to pay. In fact, it is often the easiest way to pay.

I studied in a university in a country where you have a dual-track system - either you get in for free, but have to pass a far more rigorous exam (since you're competing against everybody else who is trying to get in for free), or you pay and get your spot. The people who paid their way in - or rather, whose parents paid their way in - tended to do that "doing their time" thing you described. The people who were studying for free were far more determined to make all the efforts that they had to put into passing the entry exam worthwhile.