> Instead a building, or anything at all, is worth exactly how much other people are willing to pay for it. No more, no less.
The point you're missing is that buildings need valuations much more frequently than they are sold. CRE is generally mortgaged to the maximum extent possible (to use maximum leverage), and those mortgages need frequent re-upping as the commercial real estate market does not work like residential where you can get a 30-year fixed. So the property needs to be constantly valuated so that the banks know how much equity the owners have in the building (and if the loans are underwater), and this is being done constantly, way more frequently than the individual building is actually sold. The most common way to do this is to look at the price the building was last sold for, see how rents have changed since then, and use that as a modifier on the last sold price. (Or just a flat multiplier on top of total rents.)
The point you're missing is that buildings need valuations much more frequently than they are sold. CRE is generally mortgaged to the maximum extent possible (to use maximum leverage), and those mortgages need frequent re-upping as the commercial real estate market does not work like residential where you can get a 30-year fixed. So the property needs to be constantly valuated so that the banks know how much equity the owners have in the building (and if the loans are underwater), and this is being done constantly, way more frequently than the individual building is actually sold. The most common way to do this is to look at the price the building was last sold for, see how rents have changed since then, and use that as a modifier on the last sold price. (Or just a flat multiplier on top of total rents.)