EDIT: While I’m inside the edit window, let me throw in another big variable as an example. Costs are another factor that inform a price, and a big one. You could make a case that it deserves higher billing than supply and demand, but if your costs are $X but you can only sell your widget for $X-1, and not $X+>=0, then $X-1 is your price ceiling. Your business is unprofitable and losing money.
I’m trying to be careful with my words but I still seem to be leaving some people with the impression that I think supply and demand is the only variable that informs a price. It’s not, but it’s still incredibly important and often dismissed as a non-factor when discussing San Francisco rental and real estate prices with San Franciscans.