These do not constitute such a large portion of the population that you can say that folks who do not require them are rare. If anything it's the opposite.
The point I make is that heroin addicts require everything that everyone else requires, plus medical support staff that provide them with cheap and safe sources to feed their addiction. Equating this with the tools of the trade of medical professionals is absurd.
Pharmacies serve quite well and rather cost efficient for this purpose. It's not really that far away of their core business of dispensing prescrition drugs. The substance is different, but the logistics are exactly the same.
You may think that pharmacy robberies are a concern, but it's not really an issue. I accept that this may not universally be the case.
These systems are already in place. Maybe I'm being presumptuous but they have pharmacies where you come from, right?