That doesn’t affect the economics (and environmental impact) of mining the moon vs the earth for industrially useful metals.

The actual cost for Starship is unlikely to be the crazy low numbers space nerds like us are hoping for. No space launch system (including Falcon) has ever reached its theoretical minimum cost. It will be transformative, but not too cheap to meter.

By that logic building a mining base on the moon would also be far more expensive. You see how this makes no sense?

We will never build an industrial base on the moon unless we have a full reusable launch system and if we have such a system mining things on earth is just far, far, far, far, far, far cheaper.

The only reason you would mine on the moon is to build things ON THE MOON.

It's quite possible that the expense can be made comparable. Many resources available in the solar system exist in non-oxidized forms that just aren't available on Earth. Mining already reduced, pure metal nuggets is a huge reduction in energy costs and eliminates the need for refining steps with hugely toxic side products. Also have you seen how we mine many resources on Earth? Going to the moon (or near-Earth asteroids) and sifting out nuggets a few meters under the powdery surface regolith is way easier to do than drilling 2 miles underground for increasingly harder to find deposits.

The actual energetic cost of going from the moon to an Earth-capture orbit is only about 1 kwh/kg. Or about $150 per metric ton. Obviously real costs will be higher than physical limits, but you still might want to check your intuitions about just how costly mining the Moon really could be.

Ultimately we need to move our heavy industry off-earth to save our planet's biosphere. In a hundred years when there is a vibrant interplanetary economy, its possible we could eliminate toxic heavy industry on Earth entirely.

The cost from the moon to earth orbit isn't really the issue.

The problem is that to do mining you need a huge industrial base. Mining starts with prospecting. Then you need to develop the resource. You need to refine the resource at least a little. Then you need to mine that resources. Then you need to transport those resources to wherever your cheap launch option is. And then you need to launch it.

Building up such an industrial base on moon is incredibly difficult and would for sure require a massive Starship like rocket at the very minimum.

> Ultimately we need to move our heavy industry off-earth to save our planet's biosphere. In a hundred years when there is a vibrant interplanetary economy, its possible we could eliminate toxic heavy industry on Earth entirely.

Ok, in 100 years, but predicting that far ahead is pretty much useless. My point is that for any foreseeable future launching resource from earth is far more practical.

And from a money perspective it might never make sense, specially from the moon.

If its about the environment, then maybe but then you might capture asteroids instead.