I don't know how much sales people make, but I can tell you more about the cost of living in the LA area: If he isn't guaranteed 100k salary, he should not move. Even living in the outskirts it will be no fun on anything but a six figure family income. You have to calculate at least $2500/mo for renting a decent house in a safe area with good schools.
He also needs to get in touch with a good immigration lawyer. There are ways to get a work permit for your spouse, depending on the work visa he is on. There are also ways to get her her own visa that allows her to work. Let me know if you need a reference.
For more cost of living / safety / schools info go to the following sites:
Los Angeles Real Estate & Los Angeles Homes For Sale | LA Life
Zillow - Real Estate, Homes for Sale, Home Prices & Values (now has rental information)
GreatSchools - Public and Private School Ratings, Reviews and Parent Community
Let us know what he decides!
George