Earlier quoted context omitted.
In my opinion, you're reasoning about it incorrectly. What if I said: the price is the same for everyone, but people with less access to money get proportionally more assistance paying that price?
still seems weird to me. is there any other product for 18-22 year olds where the price changes depending on their parents wealth?
Those examples are varied and are not the same thing as purchasing a concrete product, yet I believe they are relevant to your question - education is a service that supports society, not a concrete product for your personal use and enjoyment. How and if you get it, relies not entirely on you at that point in your life, but heavily on your parents and in general on your family as a single economic unit to which you belong.