This idea kinda goes against the concept that houses pay more for unrefined minerals to keep the labor costs in-house. Better idea? Have the modules create high-quality metals that are used in the production of ship equipment instead of hundreds of thousands of regular commodities.
Better yet, make it so, for example, high-quality super alloy would count for several units of the regular stuff when building base modules or equipment, similar to how different fuels are consumed at different rates based on quality.
This would give your idea purpose beyond just making money. It would promote player interaction, and perhaps provide a way to get certain goods more easily depending on location.
It would also give bases a purpose beyond just being high tech equipment factories. What business does, for example, a KM base have producing cloaks?
I wanted to start this thread one week ago.. but I had to think about it because it would actually give stationowners to much power over indy miners but expect of that it would be.. awesome!
Or well, would it be possible to integrate it on NPC-bases? That would be a very fine solution in my eyes.
At least with my idea, the ore trading market would not be impacted, therefore the indy miners would not be affected. You could still take a shipload of ore to its normal destination and turn it in for monies. These new high quality commodities could fetch higher prices than their normal counterparts at npc stations, but not as high as the ore would sell. Therefore the high-quality goods' true value would be in selling the stuff to other players.