I always wanted to have an icon in NPC's window which allows us to place it on anything to sell.
The idea is:
- Place an Sell icon in NPCs' window: For example 
- Double click on it, and a Z icon will pop out (Like the magnifier 
when you appraise items)
- Click on any items in your inventory to sell that item.
Apply instance sell to normal equipments, crafted equipments under level 100, materials for example
Apply a confirmation dialog to any unique, honor, valor grade items...
This save time rather than drag items to NPC, or drop them on the ground which many crafters do.
And honestly, this help crafters and people while leveling a lot, because stats crafters craft a lot, and leveling guys will have tons of materials and equipments drops that they wanna sell.
