you used to be able to buy it linked to a garment such as a coat or a hat, but since the last major update you can no longer buy it. I purchased it 3 days before the update. Since the update after having the coat there is nothing even worth buying that compares to the stats of the triton coat.
I origionally purchased from the shops in moo shu and I'am now in Dragonsyre and havent found anything that compares with all of the new stats and items in the stores. Hopefully the old items will make a come back as it made the game more fun to want to earn money to get the next best thing.