People want what they can't have.
Countless shoes that are now "grails" to some sat like bricks on shelves.
In this case, you have manufactured hype to boost the process too.
When something is limited, legitimately or artificially, it introduces an element of competition into things. Once that happens, people feel good when they get through on a shoe or something. They feel like they won - hence the metaphor, "shoe game." In the process, they often forget that what they are "winning" is a chance to buy the prize, and that often times the prize isn't worth the price, or having competed for, in the first place. That's the psychology of marketing, and successful companies and retailers are damn good at it.