1) It just screws you over by boosting prices for all goods made with those materials in that region. Sure, you *can* do it, but that's like saying you can optionally die.
2) Can you do anything to help the local economy? Work the mines and mills often enough and actually decrease prices? It doesn't make sense for them to offer the evil choice for little benefit and not an alternative.
What are your thoughts? Is anyone else concerned with this system as we currently know about it?