The point generally is to try and use as little steel, or any other material, as you can get away with when you make a bike. 10 kg of mixed metal is worth pretty much nowt in the scheme of things whether raw material prices are high or low. The less metal you use the more effort and cunning you need to put in to make sure it all works. And the more of the effort you make the more the cost goes up, and the more the cost goes up the, the number of buyers who are prepared to pay a premium for those values decreases, so you have to make your product viable with fewer sales – and to make that work you have to charge more.
People hate to think it, but most of what you are paying for when you buy ‘things’ is ‘people’ and ‘time’ and ‘ideas’ not ‘stuff’. The direct cost of the raw stuff, and even the direct cost of manufacture are pretty much irrelevent.