Hi Marq, I suppose you're trying to figure a budget.
EXCLUDING SITE PREP
$300 SQ FT
Of course, you can go cheeper by hiring unlicensed subs and using sub-standard materials.
Site Prep is the killer. What type of reports do have in hand? soils?
Water and electric on site is a nice start.
I'd start with a good local architect (not builder). Talk only to pros with solid experience in LA County. Ask for references and check them.
For $250 -$500 an architect will give you basic idea of the site limitations.
If you decide to pull the trigger ask your architect to refer three GCs.
Be honnest with your GC about budget. Take his advice. Limit change orders. Select and order materials in advance. Pay suppliers on time. Be on site frequently. Time is $$$.
Again, work only with crews who have verifiable experience in LA Co.