Makes it easier to find good deals on the auction house.
This will put a price for each item on all stackable items in the AH. Basically it does exactly the same as PriceEach, but a little bit more efficiently (not that it really matters with something this simple). It will only load when you browsing the AH, and uses Ace2.
If an item doesn't have a buyout price then it will show the price per item assuming you bid on them - so the maths might look wrong at first glance.
It will highlight items depending on a warn price you set (/priceper warn <gold>) default:5, and if an item has a bid that is a lot less than the buyout it can also highlight those (/priceper highlight <percent>) default:10