Over the past several decades, the cost of earning a college diploma has increased dramatically, exacerbating a student debt crisis that's resulted in millions of Americans collectively holding over $1.5 trillion in student loans.

According to the College Board's 2018 Trends in College Pricing Report, from 1988 to 2018, sticker prices tripled at public four-year schools and doubled at public two-year and private non-profit four-year schools.

These private non-profit four-year schools have some of the highest four-year graduation rates, and graduate some of the highest-earning students, but they also have the biggest sticker prices.

During the 2018 - 2019 school year, the reported tuition at private non-profit four-year schools is an average $35,830. But in reality, many students end up paying far less.

Here's how. College "sticker prices" include tuition, fees, room and board (TFRB) and do not account for scholarships, grants and tax benefits. The College Board broke down what the average net price of college is today – taking scholarships and grants into account – and found that students typically pay less than the published price.

In fact, the average net price of tuition and fees in 2019 is $14,610 at private nonprofit four-year schools. These students typically receive an average $21,220 in grant aid and tax benefits.

Similar discounts are also in effect at public colleges. During the 2018 - 2019 school year, the reported sticker price for in-state students is $10,230 at public four-year schools, but the average net tuition and fees is closer to $3,740.