Max Ratz
It's all a matter of making the price NPC's buy raw material lower than someone would pay for it, and the price they sell them a little bit higher than anyone would normally be willing to pay. This way, the players can interact in the middle. For example iron ingots:
NPC buys for 5gp
NPC sells for 10 gp
This way, players will find others willing to buy iron from them for 7gp or 8gp and make a profit. If you are really in need and can't find anyone, you still have the option of buying or selling from NPC's. I used these prices for the example and don't necessarily reflect the real prices we have now.
It's all a matter of making the price NPC's buy raw material lower than someone would pay for it, and the price they sell them a little bit higher than anyone would normally be willing to pay. This way, the players can interact in the middle. For example iron ingots:
NPC buys for 5gp
NPC sells for 10 gp
This way, players will find others willing to buy iron from them for 7gp or 8gp and make a profit. If you are really in need and can't find anyone, you still have the option of buying or selling from NPC's. I used these prices for the example and don't necessarily reflect the real prices we have now.