go with this.
and if im interpreting the question right, the price could also be an allocating mechanism. Aston Martins. plenty of people want them, but their price makes them out of the reach for the vast majority of people.
however i do like her example of waiting in lines. think about Black Friday. people wait in lines all night, and this dictaes who has first go at the products. thus it (the line) allocates. the resource. (big screen TVs, computers, etc.) at the same time the price of an item comes greatly into play.