I don't know what problem you are having, but you can smith platebodies for 5 bars of whatever. There is a scrollbar you know.
Steel Platebodies +
75 exp each.
You get exactly 187.5 xp per steel platebody in runescape which is probably the best way to raise smithing cost wise
yes it is hard. you need to smith a lot of things, it should take you a couple of years. People tend to think that smithing rune platebodies is profitable. Well, it is not. Just look at the price of 5 runite bars, and compare that with the price of the rune platebody. Even if you have smithing level 99, you lose money with every item you smith. - If you happen to make the bars yourself, it is better to sell them than to make rune items.
no requirement i think is 80 smith
You cant.
you cant
You have to smith it with iron.
you cant
no you cant
you cant
You cant.