College/university education: limit book prices

There is no reason for always requiring new editions of books and paying incredible high prices for these books. Why are professional education books like computers books at around $20-$60 with lower sale numbers while college books above $80/$100 a piece ?
A lot of people a getting lot of $ in their pocket in this mafia system.
Give incentive to schools/college/etc and teachers when they use cheaper books and potentially establish a committee to review why these books are so expensive. The books should be mainly created by full time education system employees, and not exclusively by external contributors.