Things are going to decline very slowly there for a very long time. You have a lot of established people there who will sit out rather than sell and move up, you have a huge pool of people who want to live there and will stretch to afford it when the right place becomes available. It’s a recipe for frustration if you are looking to buy there. On the positive side, there are probably some deals if you’re willing to entertain less-than-optimal properties, like those with only 1000sf or no garage, etc… But if you’re looking for the holy grail in 92103, 1500sf+ SFH with a yard and a 2 car garage, you will probably have to pay up or wait a long time.
You might check out North/South Park, prices seem to be coming down there faster and there are some great houses, a lot more supply of quality places than in 92103. NP/SP is getting nicer all the time, in some ways I prefer SP to Mission Hills.
I bought in 2009 in 92103 because I didn’t want to have to keep waiting and I was sick of the place I was renting. I was worried about renting another place, you never know if your landlord is a scam artist/flipper/conman/whatever and I didn’t want to wake up to the sheriff banging on the door with a foreclosure notice. I’m sure my house has declined 10% since I bought it, but who cares I’m not going anywhere.
I predict falling prices in the good central neighborhoods for several more years but of course I’ve been wrong in the past.