[fastball]

Escaping the moon's gravity well is basically all you need to get stuff back to Earth.

[robotresearcher]

The machine that does this first has to leave Earth and land softly on the moon before it can start boosting stuff back. You can’t skip the first two steps.

[Teever]

Not quite.

The machine that does this needs to be built by a machine that is carried by the machine that is first built and launched from earth before you can start boosting stuff back.

It is feasible to build a space elevator on the moon with existing materials.

[fastball]

You could build a railgun on the moon and launch stuff back to earth.