legalise all drugs. but each drug should have a tax on it that will be adjusted based on the cost of treatment for rehab or other medical complications.

A drug has little spcietal side effects and is non addictive, practically no tax. a drug is highly addictive and bad for you? it'll be super expensive to cover for the cost of treatment.

thinking about it more clearly, it's more of a liability insurance than a tax.

imagine a drug that's basically instadeath, the insurance would have to pay a death insurance like payment, and therefore a dose might cost a hundred thousand USD. making it practically inaccessible.

edit: thinking about it more, it gives me strong libertarian vibes, and I've grossed myself out.