I really think your are underestimating the skill of hobby chemists. My point was that even a sophomore college kid could do it, the actual dilution is not that difficult. There's a lot of money here and it attracts even comparatively well educated people. The entirety of LSD in the 80s was coming from like, one researcher I believe.
And yes, killing your customers is something that both blows up and harms them financially. Nothing will get your small basement raided faster than druggies dropping like flies. That isn't to say they suck, only the sucky part isn't going to be something that simple.