Housing costs in Los Angeles remain astronomically high compared to outside California. Estimated median house/condo value today is at $499,000.
The site http://www.housingtracker.net allows you to follow the trends in LA and see where prices currently stand.
For such a large investment it is usually wise to hire a real estate agent who fill find listings that meet your needs and arrange appointments.
Advertisements can be found in the yellow pages of the phone book or on-line, but make sure that you are comfortable with your agent because a good agent can help you save a lot of money.
A very complete list if real estate agents is offered at: Downtown LA.