Originally Posted by djuice
Yup I'm pretty sure it's leveling up that restocks merchants. I've currently farming the High Hall merchant that always sells (Yellow) Legendary Armors/Weapons from the Slayer's Camp left of the Harbour.

I completed the Saul Quest, level up, then straight into the teleporter to High Hall and see what new goodies he has.

Keep some quest and dont turn in 1st such as those wanted criminal quest. You can kill those criminal and keep their rings or belongings but not turning in them for exp. When you notice your exp is almost close to level up, buy something from the merchant. Then straight go turn in a quest or 2 to level up and revisit the same merchant once you level up. If the merchant offer you something new, the it can be confirm that restock happened every level up. If you just go check every level, means there is duration gap of time you took for leveling your character.