I may be exaggerating the exact number, but it's a well known fact that infrastructure costs more in California. The subway in San Francisco's Chinatown was more expensive than most modern airports... we're being scammed.
You’re exaggerating well known facts? Bro get some facts in here instead of just spewing anti California rhetoric.
A "low-cost" subway is generally figured at about $80-100M/km, and in many more countries, you'd figure more like $150-200M/km as a good number.
The Chinatown subway was $600M/km, which is 3-4× "reasonable" construction costs, and fairly far from the most expensive subway, which is I believe NYC's Second Ave phase 2, at almost $4000M/km.
The US in general is a high-cost construction country (for a variety of reasons), but relative to the rest of the US, California is neither particularly expensive nor particularly cheap.