Going to be some very expensive gas.
"Apollo samples typically showed helium-3 concentrations measured in parts per billion. That means enormous volumes of regolith must be processed to extract useful gas. The basic industrial recipe is straightforward on paper. "
Yet another reason we’ll never move into space. That’s where Bio of a Space Tyrant gets it right. Humans are able to harness gravity and make it variable. If we could do that, 95% of solar system exploration issues are magically gone.