The Diablo III Forum
has word that the ability to buy and sell stackable items in the auction house is included in the latest beta patch for Blizzard's upcoming action/RPG. Here's a bit on how this works:
As of the latest patch, stackable items can now be bought and sold on the gold Auction House. We're introducing crafting materials as the first stackable item, which includes Common Scraps, Subtle Essence, Fallen Teeth, and Petrified Bark. In the future, players will be able to trade a variety of stackable items including dyes, books, and gems.
So, what makes stackable items different?
In terms of the Auction House, stackable items are designed to make your life easier when it comes to buying or selling in bulk. Rather than having to hunt through pages of listings yourself to find the best-priced stack, you can instead select the stackable item type you're looking for, type in the amount of the item you want, and then buy that amount for the lowest price currently available to the market. This may mean that you're buying from multiple sellers at many different price points, and the Auction House will manage all of those individual purchases for you automatically.