If your UC weighted capped GPA is over 4.2, then all UCs other than UCB, UCLA, and UCSD had admission rates over 90% for applicants in that GPA range for 2016. So if you apply to several of UCSB, UCD, UCI, UCSC, UCR, UCM, it is unlikely to that you will get shut out unless you write really poor essays or miss one of the specific requirements.
If you are worried about the intense level of competition in your high school, be aware that, at any school in your reachy school list, you will be competing with an even stronger level of competition than in your high school (if you go to a “top 20” college, then all of the students there will be in a “top 20” college, not just 30-40% of them), in the more intensely competitive weed-out environment of pre-med.
The Arizona public universities are relatively easy to get admitted to (e.g. https://students.asu.edu/freshman/requirements and https://admissions.arizona.edu/how-to-apply/freshmen/application-review-process ), so if you really want to leave California and not be surrounded by high achieving competition, they may be more suitable.
If you and your parents do decide that cost matters, you may want to see if any large automatic scholarship schools are suitable: http://talk.qa.collegeconfidential.com/financial-aid-scholarships/2006094-2017-automatic-full-tuition-full-ride-scholarships.html .