I lived in Florida 20 years, Psilocybin completely legal and unregulated, there is zero black market. Its always the same
"hey you want to buy mushrooms?"
"no, why should i buy from you when i can just pick my own?"
You can't sell it but you can give it away free, the same thing is happening with Marijuana, the states want to sell it and tax it so they only give limited licenses to grow it, this is the perfect for black market sales. With Canada legalizing it nation wide we are going to see huge influx of Marijuana in all border states.