Eric Greenwell maintains, and I am sure he is right,
that increased performance adds cost and smaller size
reduces cost, and that many potential owners would
be 'happy' with LS-4 performance in a smaller and more
modern design.

What about a modern 1-26 ? Could it be made affordable
and attractive enough to sell 800-1000 copies ? Would
the reduction in performance goal from 40:1 to 23:1
really reduce the selling price a lot ? Or are we
at a point in the performance/cost curve where a reduction
in L/D [for any size of glider] does not save a bunch
of cost but an increase [whether by refinement of an
existing design or a clean-sheet new design] costs
a whole bundle ?

I suspect that the economics of sailplane production
are not driven by material costs or design sophistication,
but by issues of labor costs, marketing costs, certification
and insurance - and above all, the achieved market
share. Anyone know some real-world figures to argue
from ?

Ian