i think that was kinda topic related.
a lot of the purchases of alu frames are provoked by companies image work wich results in the trends developing.
everyone,except dirt bike companies and such,stopped building high quality steel frames,making them the expensive ones.
if the same amount of crmo frames were produced as alu frames are this times,they could be even cheaper based on the better availability of base materials for the production of steel.
iron is there in a huge bigger amount then bauxit(is it named that in english?base stuff for alu).
would steel frames go into mass production in every genre again,it would be the same price-wise.
alu is great,you sell it,then sell something new again.
steel is boring...it lasts longer as youll like your bike...
edit: if you´d just know how many alu frames broke in 60 years of the bike workshop i am working at,and how many steel ones.
and thats for trekking