Think this would be a fantastic idea to add another layer of gameplay. It would require some refinement on mechanics but the interaction would allow for a channel separate from gambling or drug dealing ultimately increasing time spent on site. Whether suffocating market gives cash or hustle points or just a competitive  game. Another way to earn and build an portfolio of commodities, stocks, FBN petition funds, city treasury notes, etc. Maybe have a stock broker to employ which allows you a certain number of trades a day.