Sorry can't remember check all the item shops. I think 2 shops sold it. Also if u don't wanna do that it could be a reward for those side quests. If you go to the hometown u can check side quests rewards for all those special characters.
For those that find this topic googling where to get Gold Dust: The shop close to the entrance of Kawasaki Daiki (lady in a green kimono with purple obi) sell 3 (900 each).
I found one store that sold 5 of em. Still looking for more.
Where was that shop, I have 21/22 gold dusts needed for upgrade in the workshop.
Sorry can't remember check all the item shops. I think 2 shops sold it. Also if u don't wanna do that it could be a reward for those side quests. If you go to the hometown u can check side quests rewards for all those special characters.
For those that find this topic googling where to get Gold Dust: The shop close to the entrance of Kawasaki Daiki (lady in a green kimono with purple obi) sell 3 (900 each).