Serious need for a warning before mines run out.

[Lazuruspit]

Any one else find it strange that it costs tools to upgrade a copper mine.

[Sigmar]

all mines cost tools to upgrade, its not really cost effective though. unless you are swimming in tools. as the upgrade increases the draw rate for the resources of the mine. depleting it faster, and once its empty you destroy it or have it destroyed by a geo who relocates the ore there.. so you lose the building base costs and any tools spent on upgrades.

BUT upgrading them is beneficial IF you need that resource fast and only have 1 mine. just dont go beyond lv 2-3 for any mine unless you swim in tools and want to "waste" them