San Francisco is completely unaffordable, but there are a few apartments for rent for under $1200. Take, for example, this studio in the Outer Richmond. For $900 a month you can get a 9'x8' unit that doesn't have a stove but does have a toaster oven and microwave. Building amenities include street parking and off-site laundry. As expected, the listing tells us that "Really only large enough for a one person stay."
·$900 Outer Richmond, 38th Ave @ Fulton, in law, small studio for rent (richmond / seacliff) [Craigslist]