Mold is natural so it wont hurt if you consume it, but I still would never smoke moldy weed or any weed that was contaminated such as laced stuff.

Indeed prohibition is the killer. Holland has the best model, but it still does not fully look at the issue of supply, so sometimes the coffeeshops are supplied by criminal entities but probably some shops just grow it themselves in conspicuous places and the prices are far cheaper then in the US.

The Dutch people are allowed to grow 5 plants for personal consumption.