Community college in my district is less than $100/credit. Students will get Pell refunds, and they are free to use them to pay for other educational costs: Books and supplies, housing, meals, transportation. If they live at home, buy used books online, and otherwise watch their budget carefully, they can have money in the bank remaining when all is said & done. Saving it to help pay for future educational costs is wise.
By the way, colleges ESTIMATE the components of cost of attendance. Estimates will be high for some, low for others, and maybe once in a while, they will be spot-on. Aid is awarded based on COA, and those who are frugal will have expenses that are less than others … and some majors will have expenses that are less than others. So it’s entirely possible for a student to have leftover money.