If an engineer is allowed to borrow $30,000 and the liberal arts major is allowed to borrow $10,000, then the school will just charge the engineer $20,000 more. (They'll probably frame it in a much better way that looks like a discount to the liberal arts major, but it's important to not be fooled by that.)
If the school charges $20,000 more for an engineering degree, that will be a clear signal that that degree is more valuable. Which can definitely change things.
If an engineer is allowed to borrow $30,000 and the liberal arts major is allowed to borrow $10,000, then the school will just charge the engineer $20,000 more. (They'll probably frame it in a much better way that looks like a discount to the liberal arts major, but it's important to not be fooled by that.)