Earthquake insurance is pretty darn expensive, and most (all?) homeowner policies don't cover earthquake damage. Source: I used to be a licensed property and casualty agent in California.
There is no cost-effective way to get residential earthquake insurance in the Bay Area.
Ahh, ok, so that means the prices likely do reflect the probability accurately...
To inject numbers into the discussion: my homeowners insurance is $965 and earthquake is $1220. More than doubling the yearly bill to be sure, but it's easy to justify given bay area real estate prices.
Is your home worth between $1 and $1.5M ?
I wonder if there's an indirect way to get cheaper earthquake insurance, by investing in industries or companies that would benefit from an earthquake, or maybe by taking bets in a prediction market.