Perhaps, something along this line?
add npc Blacksmiths that charge for thier services, rather than allowing Players to smelt:
The player talks to an NPC in the blacksmithing buildings (and remove the smelting stations from the normal crafthalls since i don't think they should be there anyhow)
The player is given a list of ingot options (they select the metal of their choice)
The player is given a list of numbers of ingots they want crafted at once (1-4 only, and only the numbers they have nuggets for will be highlighted green, otherwise red)
The player is told it will cost for the blacksmithing services a total of XX gold (based on metal and number of ingots chosen; since this could be a guarenteed success or maybe a permanent 85% or something big, the cost of services could be very very high)
Then they are asked if they have that amount of gold (yes or no)
They are asked if they are sure (yes or no)
Then the amount of ingots is taken out of the player's inventory, and the gold too, a little animation and waiting later, and the player will have ingots delivered directly into their inventory and told thank you for business done, or they will be apologized to for the failure and sent on their way.
This will make Armorcrafting and Weaponcrafting much more expensive (as it should be in my opinion). People can mine their hearts out, but it will still cost them, and if high lvl players pay lower lvls for large quantities of ingots or even nuggets, very little serious profit would be made, cuz someone will be paying quite a bit of gold regardless.