That's true, but I think that is a huge jump to make on expendables. If we are going to make that jump on expendables, we are definitely going to need some serious heavy lift capability.
Probably the most important thing we can move off planet is fuel production. The payload fraction is just too ruinous for that to ever be economical.
I agree -- fuel is the obvious commodity to do first. The Moon has copious oxygen (it's 40% oxygen by weight) and this can be extracted by any number of common, industrial methods. Even if there were no hydrogen there (although there is), oxygen is 4/5 of the mass of a hydrogen-oxygen rocket fuel load. The payback comes very quickly.
Yep!