Except we already have active mines and the like in our territories. I don't see how finding one more is going to give us meaningful income. What good is a single mine going to do when a fully developed and populated province only gives us +0.5 income? If we need strategic resources, then sure, surveying is good, but if we want to make money, the economy isn't simulated down to that degree. Unless a gold mine is capable of producing income comparable to successor states like Tinshore or Greenshore, I don't see how getting one benefits us right now.