I'm Googling and here are a couple of numbers I find:
- Median rent in Berkeley seems to be around >= $3k/mo for a ~700 sq. ft. (2-bedroom?) apartment. [1]
- Family of four estimated monthly costs are ~$4.5k without rent. [2]
I don't know how accurate that estimate is, but it's around $90k/year in expenses, which is $14k more than the post-tax salary.
Curious what your numbers are that suggest this is pretty doable. Of course I'm sure there are people scraping by with much less, but it seems like doing so would need a fair bit of creativity and not be something that would seem "very doable".
[1] https://www.rentcafe.com/average-rent-market-trends/us/ca/be...