"These are students who aware that maybe Mom and Dad aren't made of money," O'Malley said.
The percentage of families who reported borrowing money to pay for college rose to 38 percent from 35 percent last year. That figure peaked at 46 percent in 2010. Families who borrowed spent on average 34 percent more ($28,386) than those who didn't ($21,219).
Education debt is primarily the student's responsibility: Undergraduates signed the loans in 83 percent of families. Within the families who borrowed, students were the primary signer for three-quarters of the total debt.
Although not all families borrow in a given year, most college students graduate with debt, said Mark Kantrowitz, publisher of the education resource site Edvisors.com and author of "Filing the FAFSA." Seventy-one percent of bachelor’s degree recipients graduated with loans, with an average balance of $35,000, he said,
On average, high-income families spent $33,260 on college expenses while families with incomes between $35,000 and $100,000 spent $21,375. Low-income families spent a similar amount: $21,036.
The average amount spent on two-year public colleges jumped 23 percent to $13,531. Spending on four-year public colleges rose 10 percent to $23,189, while four-year private college spending was up 20 percent at $41,857.
For many, the spending won't stop at a two- or four-year degree. About half of all college students, or 68 percent of seniors, plan to attend graduate school.
"The undergraduate degree has become so ubiquitous, so it may just be that graduate school is the new college," Gross said.