Progress Deorbit & Misc

In regard to "Progress is going to be deorbited. ... Mass in LEO is
worth, at a minimum, about $600/lb. ..." I don't disagree in principle, but
the ISS is retarded by a force of about 1 Newton continuously from
collisions with air molecules in the upper atmosphere (drag), and so has to
be boosted up nearly every month. The altitude of the ISS is posted on
http://www.heavens-above.com/issheight.asp?Session=kebgchcpnjoklmldbbogeicc
(to get there you will have to registrar. But it is painless and worth it
to see where ISS is not only in altitude, but also latitude and longitude,
and when Iridium Flairs can be expected, etc.) The point is that keeping
more objects (materials) on ISS will cause more drag (unless what is added
goes inside something already there) and that will cost more in fuel to
boost it, to keep it at the assigned altitude.
I agree an ion engine, VASIMER engine, or electro-magnetic tether, which
could all provide boosts, and could be solar powered, could solve this
problem, but none are there yet and I expect there will be many more
Progress space craft before they are. Then, there are those external fuel
tanks for the Shuttle, which is scheduled to go up next Friday.
I like the question (implied), how can we invest in this?
Cheers, Jay Huebner