I think there should be something like prices varying depending on place and demand. So each location should have additional parameter telling what type of resources are common there, and depending on this, prices will lower for those specific ones.
Prices could be predefined for items, but those will be taken into algorithm taking rarity/need in mind.
Additionally, modders doing worldpacks should have a possibility to overwrite the price with custom amount, but this should be done only if they want to set custom price (usually should be avoided).
I think there should be something like prices varying depending on place and demand. So each location should have additional parameter telling what type of resources are common there, and depending on this, prices will lower for those specific ones.
Prices could be predefined for items, but those will be taken into algorithm taking rarity/need in mind. Additionally, modders doing worldpacks should have a possibility to overwrite the price with custom amount, but this should be done only if they want to set custom price (usually should be avoided).