It's a WoW addon that helps you find out pricing information (Minimum, Average, Maximum) of a given item's alternative random enchantments. To do this, it uses Auctionator's API (and database) to look at the selling prices for all potential enchantments of an item. It then sticks this information in the tooltip of the item you've hovered over.
Basically, instead of just looking at this:
and seeing that the current auction price is ~99 gold, you'll see this:
and notice that the cheapest [Lord's Cape of XYZ] is (or was recently) selling for much less than 99 gold. This lets you know where the pricing stands for a given item, and can help save time and gold for listings.
Note: Requires Auctionator Check out the github page for the latest changes.