Professors also bring in millions of dollars in grants for research, bringing in MUCH more than they receive. They also worked 4 years for a bachelors and up to 7-8 additional years of schooling to get their PhD. Around 25-30% of tuition goes towards paying professors. Universities are increasing tuition partly because of decreases in state/federal funding as well as trying to compete with each other to be more "prestigious." At any time on a college campus, you will see many construction project or a building being created or remodeled. They want to be able to brag about innovation, etc to bring in more money and say they attracted the best students/faculty than their competitors.