Over the past 30 years, average college tuition and fees increased from $3,800 to $10,560 at four-year public universities and from $18,560 to $37,650 at non-profit private universities. But external costs, such as books, housing and transportation also contribute to the financial difficulties facing today's college students. 

For the country's older college students, who make up a significant share of U.S. college enrollment, these external costs can be especially burdensome.