I understand all the permutations and that you can pay less than published COA. The OP indicated they are looking at Financial Aid in post #6. I work with FGLI students where every dollar counts. If they plan with the low-ball number for 4 years, the extra few thousand that may arise if they don’t get a quad/triple, or if they can’t find the cheapest off-campus apartment, can make a difference whether they can afford college at all.
So for students looking for financial aid, I always suggest they start with published COA and work back from there. I am posting this not just for the OP, but for those who may come along and read this thread and start planning UCLA for $30K, $120K for 4 years. They need to dig into the COA line items and understand if that number is achievable.