well there is an event going on right now one that is crafting oriented iron is the lowest level blacksmithing material in the game so people are making alts and crafting low level gear so they can fulfill daily writs to turn in and get rewards so demand is higher than normal.
your level and your crafting level dictate what material you see and are able to farm so for instance a max level character and max lvl in crafting will only ever see Ruby Ore nodes (CP150+) so its almost impossible to farm for lower level mats like Iron on a max level character unless you have a low levl alt character to farm that level of mats
I hope that kinda explains things