For home prices: Tech companies pay high wages, and can afford to follow cost-of-living increases (and have to, because demand for tech employees in SV is higher than the supply). Home prices go up because NIMBYism won't allow housing supply to increase along with demand.

If someone needs a security guard, they'll pay the least that gets them someone competent to do the work. For the employer, the question isn't directly connected to the standard of living, it's "can I get a body in the door for this rate of pay?" I'd suspect the pay won't go up, as long as the answer's "yes".