[SergeAx]

Still devil advocating. Imagine you have a well developed silver mine, which produces a metric ton of silver every week. And you have an idea that there can be a gold vein somewhere on your land plot. But to find and develop it you should spend a lot of resources, including your well trained miner workforce. Rational decision would be to maybe do some research on a "last served" basis and continue to expand your silver mine, which is your primary source of income, until it depleted (if it will deplete at all, you don't know it for sure).