In its idealized conception, college is an ivory tower where students through quiet contemplation or raucous self-discovery ready themselves for "the real world."

But as college student Korchi Yang can attest, and as 2 million college applicants awaiting their financial aid packages may soon discover, being a hardworking student these days means precisely that.

Work.

Not just the on-campus work-study variety. This is real-world work: 20 or 30 hours a week or more.

One out of every five college students works full time, 35-plus hours a week, all year long, according to the most recently released census figures. With college bills at record highs, students say it's not a choice. It's a must.

Average student debt now sits at $26,600. The cost to attend a public four-year college, with room and board, on average: $17,860 per year. Private: $40,000.

After subtracting grants and scholarships, tuition paid by students at public universities jumped 8.3 percent last year, the biggest increase on record, according to a report released last week by the State Higher Education Executive Officers association.

College bills have become so onerous for some, in fact, that last month The Chronicle of Higher Education reported on a brisk market for students selling parts of their physical selves: plasma, sperm, eggs, their bodies for medical clinical studies.

"It's fast, easy money," said Nikki Hill, a 25-year-old, full-time online student at Missouri Southern State University who previously attended the University of Kansas.

While at KU, Hill said, she sold plasma twice a week while also working at a coffee shop to pay her bills.

"College is expensive. I was making $60 a week donating my plasma," said Hill, who said she earned thousands of dollars over three years this way. "All my friends were doing it, too. I used to round everyone up and drive them all with me to the plasma center."

For the majority of students who don't go to such lengths, however, the daily working world has become the prime option.

For years, studies have found that holding a job for 10 to 15 hours a week during college can actually help students perform better in the classroom. But students today are going far beyond that limit, experts say.

Too many hours has a price all its own.

"The toll it takes on students is pretty significant," said Josh Gunn, president-elect of the American College Counseling Association and director of counseling and psychological services at Kennesaw State University. "Students are depleted, exhausted, and something has to suffer."

At Kennesaw, Gunn said, "it has been quite evident that more students than ever are carrying a full load of classes and a full-time job at the same time."

When students become too run-down to make it through even one more day of double duty, he said, they usually will choose to go to work over class to pay the bills.

Consider Yang, 23, who scrambles each week to keep her life in balance.

She attends Kansas City (Kan.) Community College, but next year she will pay much of her own way through Pittsburg State University - about $12,500 a year if she lives on campus.

Born the eighth of 10 children to immigrant Hmong parents, she is the first in her family to attend college.

Her father died, disabled, in 2010 after a stroke. Her mother, who doesn't speak English, moved to California to farm after her husband died. Yang lives with a brother in their father's home.