Actually, to be a little less biased, the University of California system are generally more costly and tend to have a better reputation, but are more research and scientific theory based. That is not to say that CSUs don't have good reps. It really depends on what programs you are looking for and that you should discuss with your counselors. UCSF is primarily a Medical school and does not have undergraduate programs like the rest of the other UCs. SFSU offers both undergraduate and graduate programs so be sure to do the research before you apply. Although less costly, you can find wonderful programs at the CSUs as well.
To give you a better idea about cost differences, I ended up spending approximately $25,000 a year at UCSD including tuition, fees, and cost of living.
My friend that went to CSU Sacramento and spent approximately half of that.
no. SFSU is "san Fran state university", like California State University, Sacramento. UCSF is "University of California San Fran" as in UC Davis. UC's are more popular, have better reputations, harder to get into and are more expensive. State Universities are cheaper and don't have good reps.