1. Turn the keypad #8 on.
2. Open your inventory to see the crafting. There should be 99 of each material. Turn #8 off.
3. Close the inventory.
4. At merchant, open store, open crafting, sell all materials in crafting.
5. Close inventory.
6. At merchant, open crafting, choose buyback.
7. Buyback 99 of each material.
8. Close merchant store.
I think I have those steps right. It took me a couple times to do it.
[Edited by Cryshal, 11/21/2014 1:16:07 PM]
It would be awesome if it gave you all the materials, but it only gives you the materials of what you already have, which means you need to do this several dozen times as you get new crafting materials.