Scarcity is a great way to make something seem more attractive and valuable. The Blues Brothers famously played ‘for one night only’ and Bernd Pichetsrieder, the great BMW marketing guru insisted on ‘always selling one less than you can’.
This kind of strategy is sometimes called the ‘velvet rope’ – ‘you can’t come in’ often makes something that much more appealing. This was also the trick behind the story of how Frederick the Great turned Prussia into a potato eating nation – he insisted that no-one but the nobility could eat the potato. The ‘aspirational’ root vegetable? Believe it.