Having hosted infrastructure in CA at multiple colos. I would advise you to host it elsewhere if you can, cost of power, other infrastructure is much higher in CA than AZ or NV.
FWIW I tired to look up some numbers, i found California "industrial" electricity at $0.18/Kwh https://www.eia.gov/electricity/monthly/epm_table_grapher.ph... and H100s using 300-700w https://www.nvidia.com/en-us/data-center/h100/ which implies a worst case marginal cost of .18*.7 = $.126 / gpu / hour. Looks like Montana is cheapest at ~$.05 / kwh which would bring that down to $.035. So there may be about a $0.09 California premium (vs the absolute cheapest possibility), which as you say is a small amount of the total cost, but could be material for large workloads.
Retail residential power in the city of Santa Clara is $0.15/KwH, I'm sure commercial could be less. Especially if you throw some solar panels on the roof.
The most expensive part would be the land, but honestly there is some pretty cheap land outside the cities.
$0.09 for the GPU alone. Add power for mainboard, RAM, and fans, efficiency loss at the power supply, networking, etc. After that another flat 30% for HVAC, since all that "consumed" electricity got turned into heat and the heat has to go somewhere.
And when we are talking about low margins, a 5-10% difference in cost is very significant.
