It’s not hard or expensive to turn brown rice flour and vermiculite into mushrooms. The bit about expensive to create a pharmaceutical compound growing from a mushroom is just silly. Extraction can’t be that expensive.
My (entirely pop-culture based) impression is that "white powder" and similar processed substances of high purity are the dominant form for almost all drugs. Cocaine isn't sold as leaves, nor can you buy dried poppies.
Marijuana is an exception because it easier to smoke in its more natural state and, let's face it, because its users are hippies beholden to the naturalistic fallacy. But THC and that-other-stuff-I-cant-remember are available as concentrates.
Given these preferences, psilocybin is the outlier where, as far as I can tell, only the raw, natural form is available. Since the taste is so awful it's close to legendary, I think we can exclude market preference as a cause. That leaves the extraction being rather difficult as the most plausible explanation, doesn't it?
Not to detract from your point, but there was a lovely, decade-long period where coca tea leaf, packaged in tea bags, was readily available online, including from Amazon.
I miss that, because I have no interest in cocaine powder whatsoever, but coca tea is a nice change of pace from caffeine-based natural stimulants.
With respect to psilo(cy)bin, there's a product one can find sometimes called 'tootsie roll', which is a concentrate of the alkaloids mixed with chocolate and other confectionary ingredients. A simple alcohol extraction will do the trick, and ordinary acid-base workup can get whatever degree of purity is desired.
The phosphoryl group is somewhat delicate, which means what you end up with using acid-base is mostly psilocin. But no one actually cares about that ;)
I don't think we can exclude market preference. Dried mushrooms are harder to fake than white powders, so it increases buyer's confidence that they're getting the real thing.
I'd love to hear someone actually quoting dollars per milligram, and do an actual cost-benefit comparison between the mushroom production pathway and this novel yeast pathway. You can produce mushroom juice in a H20 solution cheaply at home for about $0.1 per 10mg of psilocybin. If you want pure psilocybin, it needs to be extracted from such a solution, but I am sure some similar extraction is needed for yeast-produced psilocybin as well. Obtaining psilocybin from yeast sounds like a great technological breakthrough, but I'm highly skeptical of economic arguments where no actual numbers are presented.
