User blog comment:Beboper/Ultra Rare Price Guide Update/@comment-5791178-20121126033724/@comment-5428123-20121126040445

The arrows are supposed to indicate trends. An up arrow indicates prices which are on the rise, while a down arrow indicates prices which are falling.

This wasn't in the description, but instead was added in response to feedback below.

If you have any comments or suggestions you want to make feel free to make them now, as I want to get the price guide up and running sooner rather than later.