Hello astrygin

Wow… The first comment that I am responding to.

What’s more, a comment from someone close to home… I actually live in the LA are (Chatsworth). Small world huh?

The costs involved vary depending on the soil conditions and severity of the slope involved. Retaining walls can get very expensive.

There is no way that you are going to develop a strong enough sense of which site is better than the other. Therefore you will need to go about getting your project off the ground in the following sequence:

First; go and drive by the available sites, simply to form some kind of a sense of what the asking prices are.
Seconded; talk to a couple of local architects, builders and engineers. Get an idea of average pre square foot prices to build.
Third; re-visit sites for sale.
Fourth; ask for a due diligence period in escrow (to check on feasibility) and then open escrow.

The four steps outlined above will very often run concurrently. The key is not to leave any of them out or else you will paint yourself into a corner. And an expensive corner that can be!

With all due respect to all real estate agents out there, please remember that they simply don’t have enough information about the subject to be helpful. Of course there are exceptions.