That price makes a whole lot of sense for an item like this, to be honest. Similar items, the Orb of the Sin'dorei and the Orb of Deception are both pretty rare. It's unusual that this one was so cheap, but it's probably a side effect of the item originally only having one charge in earlier incarnations of the item. Nowadays it has infinite uses but with a cooldown, so that higher price is deserved. You still have a chance to get it before the price change, and I really recommend you do. Especially when you consider the other change coming to the Relics and the Sons of Hodir.