I don't want to start a flame here but do you have any experience with manufacturing? Why don't you buy yourself a $12 hunk of steel and make your own tank. As there is obviously no value in the tooling investment, liability insurance, shipping and retail network involved, not to mention the 10,000 other minor points I am overlooking, please let me know where to send my $24 (I want twins).
As we have deduced, material costs are a secondary consideration when comparing steel and aluminum tanks. The manufacturing process between the two materials are vastly different but may be quite similar in end cost. There isn't a significant diff. in weight between steel and aluminum tanks, so shipping shouldn't be the reason. Also, steel tanks have a reputation for being far more rugged than aluminum tanks. I think that maybe some of these supposed advantages allows dealers to charge more for steel than aluminum and for no other reason. BTW- if you think the Faber tanks are junk, take a look at the rating for the OMS branded Faber's (10,000 fill cylces at 4,000 PSI).