@happymomof1 has the right questions there. Until we know those answers, hard to say what the comparative costs are. You say you have a $10k gap at UCD, but it we don’t know if you have loans and work study in your aid package. If you do, it is a problem as to where you are going to get that $10k gap, especially if you still have to buy books, supplies, personal items, transportation, etc. So, is the $10k gap comprised of what you will need to pay UCD after they have already maxed out aid (incl Direct Loans and Work Study) or are those resources still available to pay for things not direct billed by the school?
Commuting is not without its costs. It’s easier for families to include them in their overhead and not separate out that shampoo you are using, the addition to the electric used at the house, the food you are eating. It’s not like you or your parents have to lump sum pay those expenses. A half hour commute is not cheap either unless someone is dropping you off at school enroute to where they are going anyways. If you need to get a car, it means major expenses. I know someone who is saving a veritable fortune with school on line this term because the monthly Train and subway cards add up to $350/month, not to mention the buying meals and snacks for the day. Where I was working, for kids to go to Comm College 45 minutes away often meant another car had to be purchased with attendant costs of maintenance, repair, gas.
My cousin had one commuter and one who was living at college. Both now at home due to school closure and she’s saving money on the commuter but dishing out more for the one who has moved back home. The gas and eating out money She was dishing out to the commuter has ended but she now has to feed and supply necessities with additional cost to the one who was at school and pay g for that stuff out of pocket.