Is there a big difference between the cost of living in LA and SF?
SF's cost of living is much higher than LA. I don't know how anyone who makes below 100K a year makes it there on your own. You must have 4-5 people sharing a single apartment or something, which doesn't sound like a good time unless you're somebody just getting out of college. I'm going to guess if you're willing to commute forever and a day to and from work, you might find something that won't put you into debt. I think people pointed out somewhere else that some of the Giant Bomb crew do a long commute to deal with the living situation. All my friends/colleagues who work or have worked in SF had to do the same thing, too.
LA is pricey, yes, but if you know where to look or are willing to commute, you can make ends meet on a pretty average salary. I mean, having a roommate or two makes living in LA, IMO, very manageable, but not everyone can do that. If you're on your own, it's pretty tough. You can maybe find studio apartments in remote parts of the San Fernando Valley or Orange County that are ~1000-1100 a month, but a 1 bedroom will start at a least ~1500 month if you're lucky or willing to commute. It's mostly people who want to live close to the happening spots (near downtown, near Santa Monica or anywhere on the west side) and avoid a lengthy commute courtesy of terribad traffic that are stuck with insane rent rates (those 1800-3000 a month for a 1 bedroom type places). But then again, some article came out recently saying 57% or so of the people living in LA can't afford to live there.
There is a way to make rent affordable if you know people, but again you have to be okay with any of the following: 1) roommates 2) probably living further away from the key hotspots in LA and 3) having to commute through one of the worst metro areas for traffic in the nation. But for those saying some people should just move to other parts of the country where it's more affordable, it's kind of hard when you're cut off from the resources you need to make your content. IMO, people have to stay in LA, it's where most of the industry is, it's where most of the biggest events are, etc. Maybe just being in SoCal is enough (so you could move to a cheaper part of the area outside of LA proper), but I'd personally want to be in CA for this type of thing.
Also, the other hotspots for this type of stuff ain't cheap, either. Austin, TX, is getting ridiculously expensive if you want to live anywhere near downtown. Dallas is also getting pretty expensive (my apartment complex has raised overall monthly rent for all lease terms by 200 dollars since I moved in in Dec 2014). New York is super expensive. Seattle is getting expensive. And you can't just live in "any part" of the country and do this. Basically in general, the rent's too damn high, so might as well stay put with your friends and a place you're familiar with rather than uprooting and moving for something like this. That's just my thoughts.