"The piece that everyone forgets about this is that while the raw mineral resources themselves have some value, they have another feature that is extremely valuable, which is that they are outside of a deep gravity well."
And so we deduce that the resources, outside of the deep gravity well, are only valuable to communities living outside the deep gravity well. Ie, nobody. There is nothing up there worth something to people _down_here_.
I believe that this is a highly non-trivial bootstrapping problem. You need unimaginable technologies in orbit (power satellites? nano-materials that can only be built in zero-gravity?) to make it worthwhile to go up there and start the process. However, nobody will come up with those technologies until there is a huge industrial base in orbit... So it is impossible to get started.
Sorry to be a downer. (No pun intended.)