[ummonk]

The earth is made out of iron. There is no point in mining it in space, and regardless anything mines in space would be far too expensive for a use like this, which is why the main prospects for asteroid mining are precious metals.

[incompatible]

Yes, iron ore is mined in massive quantities in Western Australia at a cost in the order of $100 per ton.

[sbennettmcleish]

Yes, we're not gonna run out. WA ships nearly a billion tons/yr.