There are many situations where the amount someone is willing to pay does not equal the value of something. Like you point out. Anything with negative external

There are many situations where the amount someone is willing to pay does not equal the value of something. Like you point out. Anything with negative externalities is in this category. If value is derived from peoples experiences. Why would the experience of the customer count for more than the experience of another person affected by the purchase? Another problem is that we (people) are not always good at deciding what is good for even ourselves in the long run. We are not homo economicus with perfect awareness of all effects going forward into the infinite future. That doesn't (always) mean people should be forbidden from making "mistake" purchases that they will eventually regret. But it means the value of the thing wasn't what they thought when they bought it. In short: they're not the same.