Space Miners Will Bring "Trillions of Dollars" to Earth

Exactly, in theory fuel stays there for use and precious metals get send back to Earth. It’s like having a gas station in orbit.

Estimated LEO payload cost per lb (kg) = $4,729 ($10,416) on a USA Space Shuttle Launch.

One gallon of water is ~8 pounds, making it around ~$35 thousand dollars to put a gallon of water into space.

So when you want to drive to California instead of having a trailer with you that has all the gas you will need it makes more sense to stop and fill up on the way.