As long as you bring up the question of thinking things through, let me point out that drugs supplied by the Boards of Health at cost don't, by definition, incur any cost to the Boards of Health. Along the same lines, it's difficult to know how many dopers would avail themselves of the opportunity to get their drugs for very little if they're willing to have their local Board of Health certify their addiction. My guess, however, is that most of them would.
Thinking things through is a great policy. You should give it a try.