There are several large ones in Sunnyvale and San Jose, too. But even mobile homes are expensive in Silicon Valley by the standards of most other places; at this point, $150K would be a steal, and prices approaching $300K aren't uncommon -- and monthly land rental fees in the park can easily be more than the mortgage. (For instance, a listing I just pulled up on Zillow is a reasonable-ish $155K for a 3br/2ba manufactured home in Sunnyvale, for an estimated mortgage of just over $600 a month...and a rental fee of another $1600 a month.)