I was making $100k and was able to find a small apartment in SF AND save about $2k a month (granted, I've finished paying my student loans). Not needing a car, and the ability to walk / scooter / public transport everywhere for relatively cheap, is a huge money saver! My half of the rent each month, as of today in SF, is $1300 ($2600 for the whole apartment in SoMa), but you need to take into account the money I'm not spending maintaining a car (which can be costly in the city, especially w/ parking).
As for health insurance, you'll more than likely find a job that offers that. I had great health insurance, the company had some neat perks like a gym membership, free lunch and dinner at the offices, and permission to work from home pretty frequently.
I think if you are anticipating $100k a year in SF, you'll do fine!