Buy orders for auction house

As some items are not available at all times on /ah, I suggest adding a feature where players can post an order for the item they want, with the quantity they want of it and the price they want it for. Like sell listings, they would expire after a certain amount of time. To keep everything organised, they should have their own separate section that isn’t visible by default (like recently sold aren’t shown by default). This would be especially useful for items that are commonly needed for streaks.