Basically,going back to the first guy suggesting this.
I think what he meant was,lets say u are in a hurry and u are looking for a girl in that price range then all u have to do is click on it without having to go through all the girls for €100 per half hour,i personally would use it.if u then find nothing u like u can upgrade ur choice to the 100 per hour or 120.it basically makes the search easier.