Answer:
"if your use will increase, decrease or stay the same with legalization (meaning higher prices)"
The prices in Scandinavia are about €10/gram for average quality, that's half the price for 1 gram of gold, you cannot possibly assume the price of Cannabis will near the price of gold if it was legalized?
The price of Cannabis (or any drug in general) is proportional to its illegality, i.e. if a retailer is imprisoned for 1 year the price i €10 and if imprisoned for 2 years the price is €20.
The most likely way price will increase with legalization is if it is heavily taxed, although this is contrary to the point of legalizing as an illegal market is created if the legal product is more expensive than the illegal one.