[Sirius Lee]

That's a whole lot of rebar and steel framed buildings.

Good luck taking off from such a planet with your payload. Assuming you survived the "landing".

[zeestephen]

Re: “Good luck taking off from such a planet with your payload.”

I have a feeling that trying to mine or refine basic materials in space, or in near Earth orbit, will never be commercially viable.

Rare minerals and rare elements - maybe.