Quote Originally Posted by CodeCass View Post
My FC actually has this already. I was going to ask if buying from him would be better than buying from the MB or the Guild Merchants.
The Materials Supplier has what the guild merchants do, but consolidated in one place rather than spread across eight different crafting guildhalls in three cities, so it's a significant convenience advantage (though no actual change in what is or isn't available). If you've built up reputation with the beast tribes, however, some of the crafting mats they sell are not available from other NPC merchants, not even your Materials Supplier, so as you start to out-level the supplies the Materials Supplier has, you'll need to consider when it's worth traveling around to the beast tribes to buy the next tier of mats.

The market board is more variable. Occasionally you can find items there that are actually cheaper than what an NPC would charge you for them, but more often it's more expensive there. People buy mats from the MB either for convenience when they don't want to travel around to find the NPC who sells an item, or when it's an item that isn't available from any NPCs.

XIVDB.com or the Libra Eorzea iOS/Android app can tell you which NPCs (if any) sell a given material (and for how much). Personally, I think the Libra Eorzea app has the better interface of the two for finding things.