re: I'm very skeptical about lunar economic development
What is bad about all this is they Luna branch of space fans say economical reasosn are the only reasons to do space.
You have to pay back the tax payer...
And I don't think their economic arguments hold water.
If you want a fuel depot near the Moon water would be the best and stablest choice.
But, you could extract water from Martian atmosphere without the heavy equipment needed in mobile robotics on the Moon.
I don't know if it would be cost effective or economical, but it's worth investigating over regolith extraction of ices at the Moons's poles or oxygen extraction pretty much everywhere on the Moon (lots of oxides in the soil).