Drug trade in GTA is a fantasy I've had ever since i've watched scarface for the first time.
I've thought about it a lot and how it could work but none of us think the way Rockstar does, mostly because their first interest is to make money and because they understand the limits of manpower in coding for a video game, I recently learned a bit about coding and I realized it's not so simple as making a demand on a forum.
So to make a gameplay feature work within the parameters that rockstar have followed throughout their history I decided that Drug Trade could work in the same way as buying a property in GTA V , basically the property you buy is your front for the money you make from selling drugs , drugs wich you get from seeking sellers, stealing them or making them ;each with their own pros and cons:
1.Seeking sellers , would be the safest way to conduct business because you're not provoking any party , but the downside is that you get less as a result of using your own money to later sell at a profit
2.Stealing drugs , is on the contrary the most dangerous way to aquire product for obvious reasons ,you can get around a counter attack from the poor victims of robbery that you have just violated by sending a stickup crew to do your dirty work , this method is unreliable sometimes because they can get killed and if they don't you have to give them a cut of whatever you make of off whatever drugs they stole.
3.Making your own product is kind of a middle ground between the two because of the different drugs that you can make the quality and therefore price of the product is obviously affected by how good your manufacturer is .
You will have employees who work for your business and also the people who work in your drug operation who will each be compensated for their efforts ,leaving you, the KINGPIN with your cut , could be small could be big all depends on how well your business strategy is.PS If Rockstar goes for 3 characters again each character could have their own types of drugs they sell, for example Trevor :Meth