Admin covers camp costs, insurance, bean counters, health...

Admin covers camp costs, insurance, bean counters, health safety, training etc etc. Soon adds up. Aslo there will be royalties too.
Native copper won't pose a problem during mining.If it can fit in the bucket, the rock-apes will dig it up. Big chunks will be a pain in the crushing circuit where the crushers will treat it like chewing gum. All do-able though.