It's hard work but 'back breaking' would be a misconception. These guys are encouraged to work safely and smart and as a result often have careers that span 20 to 30 years.
I wish more people knew about how amazing jobs in the trades can be. I've lived in the bay for most of my 20s now and have seen quite a few blue collar folk do extremely well.
Right now in the bay we have IBEW journeyman electricians making around 200k a year. Shoot. Pipefitters, Ironworkers, they all do well.
Establish yourself in the industry and save your money. Then you can take your talents else where and live in a location with a normal housing market and habe nice things.
I've been living in SV on and off for the better part of my 20s now. I make much less then most software people but have managed to make it by financially out here.
My best advice would to be open of the idea of not living alone (at least while you first come out here). Find like minded roomates in a house in and pay 600-900 bucks for a room.
I barely make 60k a year and am doing it just fine I just don't get to have the same perks as othera.
It reminds me of a buddy who moved out here from the east coast to live here in the Bay with essentially nothing.
He racked up a bunch of credit card debt and slept on our couch for about three months but ultimately was able to land an amazing gig in SF and is now doing great.
Wondering when I'm going to fold my hand a do the same type of thing.