I know ... Rates are a little more expensive in Palo Alto, but those helpers who ask for $2x/hr can drive well and speak English! And usually the working hours offered are less when people are willing to pay more per hour.
Overall, live-in nannies are the cheapest so some people would rather hire a live-in nanny if they don't mind to live with a stranger.
yes, usually live-in nannies are more responsible as they also live and eat with you! also, they are mostly newer immigrants so they are more willing to work harder and less arrogant. however, I don't get used to live with a stranger! if I knew that I would have a second kid, I would have moved to a house with something like an in-law unit (with separate entrance) for the live-in nanny!
I had tried to hire a live-in nanny from S.F. when my little one was a few months old, but my older kid was so emotional that he wouldn't share the bathroom with the live-in nanny! anyway, eventually the live-in nanny decided not to come, cos her daughter told her not to as she wouldn't have any privacy when she works as a live-in.
Anyway, actually I don't mind to pay $2x/hour if anybody has any good referrals, although usually I wouldn't start with that higher rate until the helper had proved that she's good!