For the most part, Maroon Dollars are just like actual money except you can’t spend them everywhere and they disappear in June. So buying anything beyond what the College includes in its meal plans only makes sense for a very narrow set of circumstances.
Getting coffee/a snack/whatever at a campus coffee shop (that isn’t Grounds of Being, which is cash-only)? Maroon dollars stretch your dollar further, if you’re certain you’ll spend a certain amount, because large purchases (usually $100+) come with a bonus and prices will be the same for Maroon Dollars or another form of payment.
Getting random snacks, cleaning supplies, etc. (i.e. 90% of non-cafe purchases) from South Mart? You could get the same thing for 2/3 of the price a block away at the new Jewel Osco using Normal Dollars™.