The suburb cities are becoming just as expensive as the city proper in Southern California.
You'd have to go to Santa Clarita or Palmdale to see significantly cheaper rents right now.
Not really the case in SCV. I was in Santa Clarita my first two years in LA--it's really no different in price compared to the rest of the city. I was paying around $2400 for a two bedroom both years. Canyon Country is cheaper, but I don't even know if people consider that apart of LA metro.