you can get pretty cheap rent if you don't mind living in sketchy areas. I lived on treasure island for a few months, and besides feeling like the set of a zombie film, it was alright living for ~600pm
I lived in the mission for a little more. Definitely try the east bay for cheap rent- if you don't mind getting the bus/bart into the city the rent is a lot cheaper.
that, and the high density of crack/meth heads on the island. i checked a few places there that made me feel like i was living the american version of trainspotting (down to the baby scene).
i'd recommend avoiding treasure island.
somewhat related, scratch the north bay off your list. i never was able to find a cheap way to commute from there.
That's not necessarily the catch of TI, the Marina also suffers from that unfortunate side effect during earthquakes. The real catch is that nobody knows how toxic the soil is.
I lived in the mission for a little more. Definitely try the east bay for cheap rent- if you don't mind getting the bus/bart into the city the rent is a lot cheaper.