Some of my friends actually leverage this into justification for buying sugar in pharmacies at a ridiculous markup. I confess to being aghast whenever this happens in my presence.

If one believes that the placebo effect is true, it still doesn't justify this sort of activity when its possible to buy sugar from a supermarket, put it into pills and take it, because even if you know its a placebo, it still works

Furthermore, if placebos have no effect, then how do you explain the fact that "a placebo can reduce pain by both opioid and non-opioid mechanisms... In the first case, placebo analgesia is typically blocked by the opioid antagonist naloxone, whereas in the second case it is not." This shows there are objectively measurable chemical changes taking place, and as has been said elsewhere, the brain does affect the body, the deleterious effects of chronic stress being the most obvious example.