I think the GP's point (perhaps not articulated well) is that we shouldn't even try to quantify the value of public goods like this, in dollars. For example, a

I think the GP's point (perhaps not articulated well) is that we shouldn't even try to quantify the value of public goods like this, in dollars. For example, a smallish local park in my neighborhood is completely free and generates $0. Various entities spend some decent amount of money to maintain the park. The value is in how many people visit the park and enjoy it, which is inherently not quantifiable. The only thing you can quantify is how many people visit the park each day or week or whatever, and, say, the average number of person-hours it is used per time period. Maybe those are useful metrics that can help inform whether or not the park's existence is justified, or as to how much money should be spent maintaining and improving it, in a very rough sense. But that's not the same thing as quantifying its value.