Abyss Anglers: Pearls to the Abyss

After the achievement Abyss Anglers: Depth Grease was granted on 5/12 and after weekly reset, the Depth Grease upgrade was finally available to me. I was then awarded the achievement Abyss Anglers: Pahk Trench Fins and was able to buy the Pahk Trench Fins upgrade. However, the Reinforced Joints upgrade is still not counted for this achievement.

[item=253626] is a limited-stock vendor item needed for the Abyss Anglers: Pearls to the Abyss.

The fastest way to get this item:
1. Create an allied race character (they start at level 10) on a dead realm
2. Enter Chromie Time
3. Fly to Zul'Aman (as Horde, you can port to Undercity and fly from there)
4. Transfer the currency and buy the item

I checked the vendor on my regular characters so many times, but I was never lucky. When I tried this method, the item was available on my first visit.

Reinforced Joints aren't showing up at Depthdiver Jeju's Inventory.