If anyone wants a recent update, I live in Berkeley right now, about two blocks from the southside of campus near the I-house area.
I live in a one bedroom in an apartment complex (with parking) for about 1250 a month, parking extra (70). My building is pretty nice for the area, and really close to campus, so its a bit expensive, but I share it so its down to under $700 a month for me, so very doable. Most Berkeley undergrads can find housing below $900 at the most (unless you want your own studio or one-bedroom, then its at least $1000), easily within $600-800 for your own room in a shared apartment/house. Most grad students here seem to live a little farther out because they're not used to paying so much from their undergrad locations, so I'm assuming they pay even less.
As a side note, I'm sort of pleased to have lived in an expensive area, because now almost all my possible grad locations seems so cheap!