You know...
Launching the raw materials to orbit from Earth might cost $3000/kg.
While Earth is great for being able to sustain life, the gravity well rather sucks.
Launching the same materials from most other interesting places in the solar system would cost a lot less, (at least, were there people there to provide some sort of settlement)
For instance, presuming most of what you need is silicon oxide anyway; launching the raw material from the moon and transporting it to earth orbit easily costs MUCH less fuel than launching it from earth.
* Earth->LEO: 9400 m/s
* Moon->LEO: 1730+680+3260=5760 m/s on rockets alone
* Moon->LEO 1730+680=2400 m/s with aerobraking (smarter)
* Mars->LEO 6300 m/s with aerobraking
* Asteroid belt->LEO between 1060-3360 m/s
Moral of the story: Don't launch your stuff from Earth if you can at all help it.
Now, once you have a somewhat established moon settlement that can take on projects it gets even more interesting. Unlike on earth, Lunar gravity is so low that things like a space elevator or a linear accelerator are practical with even todays technology and materials science. Combined with aerobraking on the other end, you could ultimately ship materials or goods to earth for cheaper and faster than china post ship from china. ;-)
The only downside: first you do need that settlement on the moon, and that's one heck of an initial investment. On the other hand: once established and marginally autonomous, you can intuit that -despite harsh conditions- such a settlement could be quite a competitive location to establish mining and industry.
Reference (assuming this one is well made):
https://www.reddit.com/r/space/comments/29cxi6/i_made_a_delt...