Not really related to undercutting specifically but I've noticed people selling materials in the market for what the NPC turn in price is. I have to say this is just ridiculous, you want to wait for your item to sell for the same gil you can flip it to an NPC for???? umm ok.

I have to say the undercutting is getting frustrating for making gil from crafting / farming. But leveling crafting is a lot cheeper. I'm just not sure if it balances out.