You are quite right about the costs of doing any kind of road or rail expansion in Southern California. Unfortunately, this includes the HSR section that will go between UC Riverside and LA, with a spur down to Anaheim (see
http://www.cahighspeedrail.ca.gov/uploadedImages/Routes/Project_Sections/Preferred_state_map_FINAL.jpg ).
I lived in Southern California from the '50s until the early '90s, so I remember the "golden age" of freeway construction there. Most of it was done by the '70s, and each project became more and more difficult as land became more expensive and people objected to the disruption. The biggest example of this was the Foothill Freeway. The western half was completed in 1976, and the land was purchased for the eastern leg to be built next. But people along that route objected, lawsuits were filed, and the freeway was not built. Caltrans struggled for years to keep the right-of-way on the eastern half. Finally, the need for the freeway outweighed all the objections and the eastern half was built starting in 1990. It wasn't completed until 2007, the eastern half being about 40 miles long in total.
My point here is that it's going to be EXTREMELY difficult to get the right-of-way in the LA basin for the HSR. The route largely parallels the Foothill Freeway, so we already know it's going to face fierce opposition. Sure, some people will be swayed by the idea of HSR, but for many communities it will be just another wall dividing their city in two. Given that there will be only about 8 stations in the LA basin, most communities will see the HSR cut through their boundaries without any way to get on it except by driving miles to the nearest station. It's clear that the strategy to build the sections in the middle of nowhere first is to cynically justify the building of the HSR line later in the LA and San Francisco regions (who says bureaucrats are mindless sheep?)
Note that including Palm Springs there are six regional airports in the LA area to fly to anywhere in California, and they are more widely dispersed.
