Tuition at my university for undergraduate study if living off-campus is estimated to be $18,600 a year (if a resident of California.) Graduate study is about a grand extra. I would say that is about average for all of the Cal States, but a U.C. would be significantly more expensive, and private universities even more so. It depends on where you want to go.
As an undergraduate student, I paid absolutely nothing. My friends are envious of me. I was completely lucky that, at the time, our state had a decent offering for students in my situation (low income family). I would not have been able to pay my way through college and earn my Bachelors without federal aid.
Now that I am a Masters student, my situation has changed slightly. I am still receiving federal aid, but a significantly smaller amount. Each quarter, I am required to pay $220 in tuition, roughly $100–200 for textbooks, and $70 for transportation (I commute by bus.) So I am paying approximately $490 out of my own pocket.