[quote=@WilsonTurner]
<Snipped quote by Aristo>

What about aluminum alloys?
A lighter, maybe not quite as strong as steel metal that's more expensive, but you can bulk up a bit more with it to be more maneuverable and even more protected than before?
Probably gonna be over three times as expensive tho XD
[/quote]

It really depends on what FRAME you've got; the "durasteel" our Zarugas and Handous have is a steel laminate armor, with aluminum plates sandwiched in-between. FRAMEs will have different compositions based on manufacturer and role.