Gordon,

Unfortunately, I have to disagree with you on your analysis of aluminum
use in commercially built LSA aircraft structures. While it is true that
the aluminum materials costs for an aircraft are lower, the labor costs
(which I have already shown to be the largest cost in building any
plane) are much higher, thus making it a poor choice if you are trying
to build such airplanes for a profit. On the other hand, if you are
trying to sell kit LSA airframes, then the builder assumes the labor
costs, thus making a comparable kit seem less expensive.