[Cincinatus]

and the He3 is not strongly bound to the lunar soil, even a ppb level is economically feasible.

That's highly debatable, but suppose for a moment I grant you that. What are you going to do with the 3He you harvest?

[Wonder Warthog]

"That's highly debatable, but suppose for a moment I grant you that. What are you going to do with the 3He you harvest?"

Uh, you did catch the part about fuel for fusion reactors?? Fusion between He3 and H1 (protons) to yield He4 is one of the "easier" ones to initiate, with the benefit that the product of the reaction isn't itself radioactive.