Over the course of a usual crafting list for me, I'm going to end up visiting usually 3 different NPCs to buy materials from, and at this point there doesn't seem to be really any reason for it.

For example, usually I will have to run to the material supplier in my house to pick up some copper ore. Then I want iron ingots, so I have to go to the material supplier that's outside my house, inside the actual housing ward. Finally, I need quicksilver, so I have to visit one of the capital cities to buy from the material supplier there.

What is the purpose of all this? All this rushing around to different vendors is absolutely needless. Please standardize the lists of these 3. While you're at it, though, I would also suggest adding items that are sold by the guild vendors to these as well (for example, you can purchase Potter's Clay from Esmenet at the alchemist's guild only, and it would be nice to buy elsewhere), and perhaps the Kugane/Reunion vendors. This would make things a lot simpler rather than having to manage a bunch of different vendors to buy things from.

As a final note, I don't really recommend this change for the beast tribe vendors since it's rare that I buy materials from them anyways (for most it's not very cost effective) and it gives people a reason to go to one of the less visited areas, and they also have the token exchanges. But for this particular trio of vendor types it's annoying!