Is any mineral worth the cost of bringing it back from another planet???
“Is any mineral worth the cost of bringing it back from another planet???”
If you had 50 tonnes of platinum mined from an asteroid, yes. Gravity will be a big help in Baumgartnering it down to the marketplace.
Probably not but mining planets would likely be for local use.
The real advantage is in mining asteroids. They can be moved into more favorable orbits and mined at leisure. The advance of 3-D printing could go toward manufacturing in space both for further space exploration and products for here on earth.
Some are, some aren’t. No waste disposal problem, plenty of energy available.