It's well documented that textbooks aren't cheap, but for some students, affording course materials takes priority over paying for meals or flights home, or pursuing their first choice of major.

A new study by Morning Consult for Cengage, an educational technology and services company, asked 1,651 current and former college students how purchasing textbooks figures into their financial picture. Forty-one percent of those students said that textbooks and other course materials had "somewhat of an impact" on their financial situation, and 46 percent said that it had "a big impact."

"We truly are in an access crisis," said Richard Baraniuk, a professor at Rice University and founder of OpenStax, a nonprofit that provides access to free digital editions of textbooks. "Over the past 40 years, college textbook prices have risen about 1,000 percent, which is extraordinary. Much faster than the Consumer Price Index, much faster than even parts of our economy that we say are out of control, like medical spending. Textbooks are outpacing that by a large factor."

Michael Hansen, CEO of Cengage, said the industry is out of touch with students' thoughts on textbook affordability.

"Textbooks -- and many in the industry have denied this for too long -- are a major stress factor for many students around the country," he said. "Students are making major trade-offs such as housing, such as food, to accommodate textbooks."

Thirty percent of survey respondents said they had forgone a trip home to see family, 43 percent said they skipped meals, 31 percent registered for fewer classes and 69 percent worked a job during the school year -- all to save money for books.

"Even when a student goes through the excruciating pain of searching through used books, photocopying, illegally downloading PDFs and renting books, they’d end up spending about $578 a year," Hanson said.

That figure would be closer to $1,200 per year if students chose to purchase all new textbooks and other course materials.

Over half of the student survey respondents just aren't buying some of the required course materials. Sheila Liming, an English professor at the University of North Dakota, said her students' grades have suffered from opting out of certain book purchases.

"I give periodic, scheduled quizzes in some of my classes and, last semester, more than two-thirds of the class failed one of the quizzes, which I later learned was because most of them hadn’t purchased the book that it was on," she said via email. She said that students often preform a cost-benefit analysis and weigh potential hits to their grades against the cost of a necessary textbook.

In response to the rising prices, Cengage will launch a program in which students can purchase access to all of Cengage's online materials for $120 per semester.

"A community college student will now spend more hours in a minimum-wage job to pay for their textbook than they would sitting in a course" they're buying the book for, Baraniuk said. "The cost of books per year exceeds the cost of tuition at some community colleges. It’s one of the biggest costs of going to college."

Students don't feel the costs are justified, either, according to the survey. Eighty-seven percent reported that they believed textbooks were overpriced, more so than tuition fees, prescription drugs and airline tickets, and 69 percent believe that publishers are unfairly profiting from the cost of textbooks and other course materials.

"They’re not worth it. It’s not worth it because these books shouldn't be $300. It’s just basically a market that’s completely out of whack with reality," Baraniuk said.

In addition to financial sacrifices, some students are changing their educational plans altogether. Seventeen percent of respondents said they changed their major because of high textbook prices, and 33 percent opted not to take a specific course. Of those who left their original major, 12 percent left medicine, 10 percent left the social sciences, 9 percent abandoned business and 9 percent dropped computer science.