This is a well-established and researched part of market failure. It involves the idea of negative externalities, like how a market for heroin creates a social

This is a well-established and researched part of market failure. It involves the idea of negative externalities, like how a market for heroin creates a social cost that is borne by the general public. And you're right that a market transaction is the best measure of "good" that we have. To get some sense of "what society might pay" to limit or eliminate such a market, an analyst must resort to more difficult methods like cost-benefit analysis. It's a huge topic and is used by major governments.