The U.S. Public Interest Research Group Education Fund conducted a survey which shows that 65% students had decided not to buy textbook as it was expensive. The survey also found that 94% of students who had foregone purchasing a textbook were concerned that it might hurt their grades in that particular course by doing so. So, the study opines that almost half of the students felt a substantial concern for their grades.
SOURCE: U.S. PIRG Education Fund