Plenty of influential people assume that teenagers can ask parents for loans if all else fails, as Mitt Romney suggested during the 2012 presidential campaign. Others recall working their way through college themselves, including Representative Virginia Foxx, a Republican from North Carolina who heads a House subcommittee on higher education and work force training. “I spent seven years getting my undergraduate degree and didn’t borrow a dime of money,” she once said at a subcommittee meeting, adding that she was bewildered, given her own experience, by tales of woe she had heard from people with $80,000 in debt.

But students nowadays who try to work their way through college without parental support or loans face a financial challenge of a different order than the one that Ms. Foxx, 69, confronted as a University of North Carolina undergraduate more than 40 years ago. Today, a bachelor’s degree from Appalachian State, the largest university in her district, can easily cost $80,000 for a state resident, including tuition, room, board and other costs. Back in her day, the total was about $550 a year. Even with inflation, that would translate to just over $4,000 for each year it takes to earn a degree.

And the paychecks that Mr. Tolmie managed in the big city are only a dream in towns like Boone, where employers have their pick of thousands of Appalachian State undergraduates. Even the most industrious, like Kelsey Manuel, a junior who drives 10 miles each way to a job in a resort where she earns $10 to $11 an hour, often cannot work enough to finish college debt-free.

No one tracks how many students are trying to work their way through without parental assistance or debt, but plenty work long hours while also attending classes full time. As of 2010, some 17 percent of full-time undergraduates of traditional age worked 20 to 34 hours a week, according to the National Center for Education Statistics. About 6 percent worked 35 hours or more.

Students who work fewer than 30 hours a week (excluding federal work-study jobs) while in college were 1.4 times more likely to graduate within six years than students who spent more than 30 hours a week in a job, according to an article by Pilar Mendoza, an assistant professor of higher education administration at the University of Florida, in The Journal of Student Financial Aid last year. Their grades are likely to be better, too, since they have more time to study.