[actionfromafar]

You would make the stuff in space, too. Give it a gentle shove off the factory loading dock (factory is on an asteroid) and a couple of years later it shows up in earth orbit, if you get your orbital calculations right…

[adrianN]

Getting stuff from the asteroid belt to earth orbit is about as hard as the other way round. Definitely more than a gentle push

[actionfromafar]

Not literally a gentle push, but very little rocket action is needed. The gravity well of an asteroid is tiny. The rest can be done with the correct slingshot maneuvers, the problem is calculating it. I am sure I have read something or other from NASA about it.

[exe34]

It's not the asteroid gravity that's the issue, it's the solar gravity field, you still have to perform an orbital transfer from the asteroid orbit to Earth orbit unless you want to leave the computer there and do batch jobs with significant latency.