Crafting materials from merchants - one time only?

[Jamison]

So I was curious. I wanted to see what the restocking of materials is. I went to the clothier and blacksmith in temple of yamu, and bought all their crafting stuff. I did a dusk till dawn about four times (two in-game days), and there still is no stock.

[Efexius]

game does not reset with dust/dawn, so if u want a npc to respawn or stocks to be full, u need to come back later, there is no other way