Yeah, SF is that expensive. Outlaying areas are not much cheaper, it's just that you get more space for your money - but start tossing communing costs in there, and it adds up.
And its not just the LGBTXYZ thing either, lots and lots of people what to live here for all sorts of reasons. It's a financial capital, a major world arts center, a high-tech hub, center for people into mountain biking, road biking, sailing, surfing - all that stuff. Berkeley, Stanford, Academy of Art, digital design, Pixar all bring people in and people interested in those fields.
Just be sure you have real skills, not just a degree.
It's hard to park an RV in any place you'd feel safe to park it.