A while ago I ran for a crew of Hawkers who wanted to produce their product themselves, not seeing anything specifically for this in the book, I rapidly threw together the following rules:
The crew’s job is to find Suppliers who will provide them with base resources and Clients who will buy the end product.
The Product has some sort of signature mark (like Breaking Bad’s blue meth)
Unless negotiated with for more, each Supplier will provide one Supply per score.
A single player may use one of their downtime actions to convert their Supplies into Product which may be sold. They must roll for Quality, using whichever stat they find relevant (most likely Tinker) and on a 1-3 the Product is severely flawed, on a 4 it is somewhat flawed, on a 6 it only has the expected side effects (if any), and with two 6s it is top quality and in some way works better than intended. Decide as a group what side effects are appropriate.
Unless negotiated with for more, each Client will pay one Coin per Supply received.
If you have more Suppliers than Clients, you will lose one Coin per score for every additional Supplier.
You may find additional Supply through scores, but these are non-recurring.
Now, as this was created for my first time running a game I made some mistakes in applying these rules to an engaging game, so I’d also like to add some best practices for implementing these rules with the benefit of hindsight:
Make sure your crew is dedicated to the idea of seeking out and maintaining relationships with Suppliers and Clients, otherwise it may just act as a passive income stream that hinders need for risk taking.
To provide conflict, aim rivals around the crew rather than directly at them, have enemies attack around them, at the Suppliers, the Clients, the supply chains, or the Supply itself. Alternatively, my favorite arc from this campaign was when another crew began selling inferior product under the players’ brand, driving down their reputation.