The funny thing is that I just plucked 5MM out of a hat for my number 5 or so years ago when asked and I guess this analysis supports my intuition.
The one big problem with renting is instability. If the owner decides to sell the property, it may be difficult to find something equivalent on your terms or you may be forced to hop around a few times before settling.
A buyout, as sibling mentioned, could happen, but would likely not be enough to make up for losing your rent-controlled apartment. In SF, most apartment rentals are covered by rent control so you can more or less predict how much rent you'll be paying years into the future (the annual rent increases are capped by the city and though they are supposed to be tied to inflation the allowable rent increases are likely, practically speaking, less than the inflation rate (for example, looks like for the coming year the increase is capped at 1.7%)).
Stability is one of the reasons why I bought a few years ago (albeit, not in the SF Bay Area). That ever-looming possibility of needing to move again come lease renewal time, whether that be due to rent hikes or the landlord deciding to do something else with the property wore on my nerves.
Of course home ownership isn’t all roses either, but I can at least rely on and plan around my mortgage payment not changing and not having to move unless I decide to do so independently.
>That ever-looming possibility of needing to move again come lease renewal time, whether that be due to rent hikes or the landlord deciding to do something else with the property wore on my nerves.
That sounds dreadful and that's why there should be laws against landlords kicking out long time tenants at their whim. Your home should be a safe space and having that sword of Damocles constantly looming above your head must feel awful especially in lower income households.
It’s not great, but what makes it that much worse is the hunt for the next apartment that one needs to start a good deal before lease renewal just in case. Just having a single small cat cuts your options in half, and then of course price and whatever other quality of life things you might be looking for (e.g. adequate windows/natural light/building facing) cut that down further. Apartment hunting is anxiety-stoking.
Let's not go too far either. IF that happens, you can live in a too expensive, or not optimal location, or otherwise imperfect place for a few months or one year while you hunt for better.
For me that scenario is all the more stressful since that means there’s going to be at least two moves upcoming instead of just a potential single move.
It's a "might have to" - not very likely - in exchange for going house hunting every year just before lease renewal. That's a lot of work every year. But sure, it's a choice.
These calculations do not commit you to a course. They are statistical reassurance. You can and should remain aware that you can course correct. For example, California weather and your friends might be your preference in San Francisco, but you can still fall back to something far less expensive.
If the landlord buys out the tenant then that typically means the unit is rent-controlled, which means the tenant does not have to leave, and their rent doesn't change, just because the building is sold (rent control goes with the building, not the owner). Just adding in case that's not clear to other readers here. Tenants can and do accept buyouts, but just pointing out that a tenant's rights under rent control do not end with the transfer of the property to a new owner.
The one big problem with renting is instability. If the owner decides to sell the property, it may be difficult to find something equivalent on your terms or you may be forced to hop around a few times before settling.