So the monetary cost absorbed by society for "what two consenting adults" do with illegal drugs is OK with you?
"ok with me" may not be an accurate term.
Am I willing to accept that idiots (drunks, dope addicts, lardasses) create cost to society over the idea of the state regulating activities I disapprove of? You bet.
Your question concerning the "cost absorbed" is the same logic the anti-gun folks use when trying to justify limiting firearm freedom.
FWIW - I do not approve of taxpayers being forced to pay for needles, rehab, open-heart surgery, etc.