We DON'T need more Lumps!

[Maestro]

Nice idea, my only question is, who gets to say what the value of each mat is? for example a bronze arrowhead is not worth a raven feather or a wood of glasir, so some items will be left with no equivalent partner mat. Or is the reason of these trading tickets supposed to cover that?

I would asume that devs by creating recipes assigned some value (not gold) and rarity to all green mats.
Other possibility is to check the statistics of AH tardes to see how the relations changed between certain green mats over time

And trade ticket is to make trading the real mats you need more profitable and keep green mats prices more fluent and sligtly independed from each other