You're right, I was loose with my words here. Worth does have a specific economic definition, but that definition is not particularly helpful when talking about an asset price like this. It is by definition individual, can only be known once the future happens, and it depends on when the realization of that value ends. This is particularly challenging when the realization of value (rent payments) on the asset (commercial real estate) is inherently volatile itself. In fact, for this very reason, economic value is generally not (usefully) measurable. So in absence of that, buyers will attempt to estimate the future value, and use that as input to the price they're willing to pay.

My point in my original comment, which I believe still holds, is that there is no objective truth to this number. Multiple buyers can arrive at different definitions of worth depending on how they used the asset and when they ultimately sold it. And even if they both arrived at the same value, it can only be known in hindsight. For example, say I purchase a stock solely as a monetary investment for $10 today, in 1 year the price drops to $2, and in two years the price jumps to $50. The answer to whether the stock was "worth" what I paid depends on when I decided to sell it. If I had to sell that stock in a year to buy a house, it certainly was not. If I could hold the asset for 2 years, it was certainly worth it (and then some). Or, going back to your example before, if the cash flow was less than I expected - that's not great. But next year it could be more than I expected. The time horizon is a critical component here, as are the factors unique to the individual buyer.

Your statement that the property was not worth that much can only be said with the benefit of knowing what the market is today. In 6 months, the asset may be worth 25% more than was paid for it. It's likely that's not the case, but clearly many people thought it was likely the asset would generate more money than it did when it was bought and were wrong. We may also be wrong today.

So, when we're talking about the "worth" at the market level we almost have to be talking about willingness to pay. We assume that will price in estimated future value. There's not much else we can usefully measure here.