Print Me a Condo on the Moon!

It still requires taking a shipload of magnesium oxide and another of binding salt to the Moon. If you could find that on the Lunar surface, great, but this sounds like they'd be bringing it from Earth.

Of course, if the alternative is bringing the ENTIRE structure from Earth, it might bee the best thing going. Also, bulk raw material like that could be launched with a Verne cannon or other high-G method which a prefabricated habitat module might not survive.