And this is the logic for a moon base. Get the volatiles from the moon and boost it to low Earth Orbit (the ISS with a large fuel tank attached). At a certain point you get less mass used from lifting from the Moon after dropping the infrastructure than you do from lifting form the Earth itself.

Why the hell was that base canceled?

Because it's boody expenisve to build in the first place - and resupply is a *****, too. At least until such time as you can move sufficient mass to allow it to start running self-sufficiantly.

The cost would beggar the cost of catching Voyager. Of course, once set up, future launches become much less expensive, but the sunk costs are staggering.

Aye but we already sunk the money into 2 of the three main parts of LEO infrastructure, the Shuttle, the ISS and the Moon base was never made (I mean an automated base for mining of volatile, minimum need for crew).

That was the system that was intended, so all of the payload from Earth would be long term infrastructure (building Spaceships at the ISS, the ISS itself and systems to recycle food and water).

Long term the plan needed around another 100B or so, but when you're 150B+ into the plan.... well just the existence of a fuel depot in LEO would have jump started a spacebourne economy there and then.

I'm convinced that this system would have paid for itself within a few years and been the big driver of the global economy after the internet had run its course in modernization in just in time production systems.