As of last year, the amount families actually paid was $26,458, on average, according to Sallie Mae's 11th annual "How America Pays for College" report. That's up from $23,757 in the year earlier.

Tuition and fees for a four-year private college averaged $35,830 in 2018-19 ; at four-year, in-state public colleges, it was $10,230, according to the College Board. And that's not even adding in room and board or other expenses.

Few purchases deliver a dose of sticker shock like the cost of college.

Income and savings from parents and students combined covered nearly half, or 47 percent of that amount in 2017-2018, up from 44 percent the year earlier, the education lender found.

"There are some families that do pay 100 percent out of pocket and some families do get a full ride," said Marie O'Malley, the senior director of consumer research at Sallie Mae. "Typically, though, people rely on a number of different resources to pull it together."

Scholarships, in fact, were the single most-used resource to pay for an undergraduate's college bill.

The share of college costs covered by scholarships and grants — money that does not have to be paid back — accounted for 28 percent of the total expense. The average total award among those who used one or more scholarships was $7,760, Sallie Mae said.

Of course, many families also borrow to pay for school. Borrowed money, or loans, covered nearly a quarter, or 24 percent of the tab, down from 27 percent the year before.

Contributions from grandparents or other relatives or friends paid for the remainder.

The report polled about 800 parents of children ages 18-24 enrolled as undergraduate students and nearly 800 undergraduate students aged 18-24 online.