I'm sure a search of Google Books or the MOA will turn up something about costs, but the first thing I thought of in reading your post was good old Thomas DeQuincy, whose consumption of laudanum approached the heroic. In the introduction to "Confessions of an English Opium Eater" he notes that,
"...some years ago, on passing through Manchester, I was informed by several cotton manufacturers, that their work people were rapidly getting into the practice of opium-eating; so much so, that on a Saturday afternoon the counters of the druggists were strewed with pills of one, two, or three grains in preparation for the known demand of the evening. The immediate occasion of this practice was the lowness of wages, which, at the time would not allow them to indulge in ale or spirits..."
But when wages finally rose, they were already hooked.
So in fact Marx was indeed wrong about something. Religion was not the opiate of the masses; opium was.
M. A. Schaffner
Midstream Regressive Complainer