Void Conch

The void conch was the most common storage item because its raw material itself contained some dimension space. It only needed to be refined a bit and it would turn into a decent magic item.

The Ranger Guild had a Wizard Alliance alchemist shop, and Marvin spent a large amount of money there to buy it as it was an essential item. This thing was obviously worth a lot, and Marvin spent 3 wizard golds on it. Storage items were very expensive like uncommon items.