Would it be possible to maybe put in that you can upgrade or downgrade materials for upgrading, IE 10 blue make one purple and 10 purple make 1 gold and if you break them down the same.
This idea has been in the forums before with mixed reviews.
It makes sense for enchanting ... since there is very little use of the lower aspect runestones (Ta, Denata, etc.)
On the other hand, purple and gold improvement mats rarity is just that ... rare. Once you start introducing more of those into circulation, the market tanks.