Define a black market, Zbniebniz. Is a black market one that follows the set laws but sells on an individual basis instead of in a shop? Then yes, the black market will thrive. It's true I refill venoms for 1,200 gold or new vials for 1,500 gold. It's also true that this is cheaper then shops are required to sell at. The Venom Laws agreed to do not require individual sales to be 2,000 per vial. Yes, they do favour individual serpents as a whole instead of those handful of serpents that own shops. Live with it and milk outside of your shop.
You call for an example. Well, I don't believe in making examples out of people, Zbniebniz. You yourself are about to become proof of the validity of these laws, however. Perhaps that will be example for you.

Penned by my hand on the 14th of Chronos, in the year 267 AF.