That's very unlikely to be true in the case of the high-school kid who died buying a synthetic drug off the internet. They almost certainly did not have a dealer connection sophisticated enough to sell that. They almost certainly would have lived, if Silk Road were not available to them at that point in their life.
You're advancing an argument about drug markets and personal autonomy in the general case, but it's a very poor fit to the concrete facts in the specific situation we're looking at.
Though I think this argument is tangential to the point on proportionality- Ross's sentence is an affront to justice when considered in the context of the Sackler's treatment
I'd rather get my milk from the corner store than some anonymous reseller on amazon. Real life drug dealers operate in markets too.
"If I don't do it, someone else will" - I suppose this is a convenient excuse that can be applied to anything unsavory, from the little guy selling shrooms at the street corner to nation states making nasty biological and chemical weapons?
Not saying there isn't truth to it, just wondering how as a society we seem to accept that doing unsavory things is a necessity because others are doing it (or they will be doing it soon, so we better be the first)