With Dutch decriminalized laws on selling "soft drugs" (weed and hashj) the market for it is actually working with competition (most idiotic thing is that growing is still very illegal in NL and actively craced down on by police).
With sales out in the open much about the prices has to do with quality. I live in a city with around 100k population and we have around 10 coffeeshops operating in the area.
Weed goes from cheap: 4-5 euros to expensive 10 Euro's per gram.
Hashj (mostly smuggled from Marocco or Afghanistan) goes for 7 euro's till 14 euro's per gram.
It's legal here and the prices between the shops and the black markets are wild.
The shops at the cheapest sell $5 A gram for some bunk stuff.
While the primo can go for $18 A gram as I've seen some 19% CBD bud go for.
While on the black market you can buy a full ounce of really good stuff for no more than $150. And that's for the top shelf.
It's crazy though, I used to sell pot back in the day for 0.8 grams for $10 which was just standered for the time.