Fresh Idea to Achieve LEO

I personally believe that it would be cheaper just to design and launch
inflatable modules, as recovering these wasted tanks would be such a
pain in the butt. Inflatable modules would not take up much cargo space
and would be relatively lightweight. What would the costs be to launch
a conversion facility and propellant to boost the orbit of one of the
external tanks? I'll bet I could lower that cost with an inflatable
station. Tether it to the Iss, or let it free float, whatever.
Inhabitable volume at the lowest cost possible is really more the issue
than if we can salvage and recover these wasted tanks. Could we salvage
them? Sure. Could we convert them into useful habitats? I have faith
that we could. But is that truly the most cost effective and practical
way?