I believe iron ingots are 19 septiums each so it should be about 400 gold each time you make the transaction. Start out by going to every blacksmith in Skyrim and purchasing all their iron ingots and iron ore. So to get this skill to level 100, make sure you have at least 7000 gold to spend.
Yes, before anyone yells at me saying “I only use magic or I only like to ride my horse around for hours on end let me explain.” Irocknight found a way of getting this skill to level 100 in a matter of hours. So before any of you go “I’m only level 13, how can I get a skill to level 100 without playing 50 hours?” Well friends, the solution: Smithing. When looking at the list, it’s noticed that one of them is getting a skill to level 100. When it does come down to it, everyone does love getting those achievements/trophies.
One might be an assassin, one might be a brave heart like player. Everyone has their different way of playing Skyrim.