Whoever bought it should plan on staying there for many years. If/When housing supply begins to catch up with demand, these ridiculous housing prices will probably crater, and some of these houses will lose half their value.
Local RE differs, as always. I've lived in the SFBA since 1969; this is what I've seen:
#1 - FYI for those unfamiliar with Northern CA RE, this is NOT a San Francisco house. It is in Mountain View, an upscale suburb within easy reach of Silicon Valley. It is a full 40 miles south of SF city/county. It's also a duplex with that legal ADU, which alone in the South Bay Area must have cost them a good $150K-200K.
You couldn't find a lot big enough in SF proper to build that home without it costing twice what it went for. The average lot is 25x100 sq. ft. in The City, as we call it. There are multi-million $$$$ old mansions in SF built on lots that are 60x75 sq. ft.
#2 - there will never be a time when "housing supply catches up with demand" in the San Francisco Bay Area, unless there is a major earthquake and half of the SFBA slides into the ocean. We are geographically constrained by mountains, state/county/city parks, watershed preserves, etc. There are no hundreds of acres of flat cheap land on which developers can throw up 3000 SFHs for $300K.
Such geographic areas exist only a sizable distance from the SFBA. Out here what goes up is hi-rise (in SF only) or multi-level (every other SFBA city) condos, because the developers are lucky if they get one city block on which to build. Usually they only get 1/2 a city block, at most.
#3 - no matter what you hear about remote ("Work From Home") employment, the vast majority of workers are not being given that option. Companies are already beginning to constrain it and require at least several days a week inside the office. Our commuter traffic is already back to 90% of normal region-wide, and the state isn't even opened yet.
I know people who regularly drive over 90 min each way to work. It isn't fun, and it's EXPENSIVE. Our gas is the highest in the nation, which is what's driving the push to hybrids and e-cars. You really do not want to be more than 40-50 miles from where you work....and these days, there isn't a single young person I know who has not had multiple employers with HQs in different SFBA cities.
Gone are the days when "everyone commuted into SF and back home again". So you don't want to tie yourself into buying a home so far away where it's just not possible to easily reach potential employers. But that means you must be closer to the "center" of the SFBA - not further into the exurbs where land is flat and tract homes pop up like mushrooms after a rain (rain? - what's that, LOL?).
#4 - In the SFBA you are always competing against foreign buyers with cash. They faded under Trump, but never completely stopped. To wealthy Asians, West Coast RE looks like a bargain compared to HK, Tokyo, Singapore or Malaysia.
And that doesn't even count RE holding corporations. A lot of hedge funds love to invest in urban RE, both commercial and residential.
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Anyway, hope that helps others understand the very singular market of an area which only exists because its historic demand has ALWAYS outstripped supply.