This is somewhat of a simplification. The wine $40+ is also likely to mature into something more interesting over time, which the $15 wine likely will not. You

This is somewhat of a simplification. The wine $40+ is also likely to mature into something more interesting over time, which the $15 wine likely will not. You are partly paying for future appreciation in quality. Of course the vast majority of wine drinkers just guzzle the bottle as soon as they come home from the store, so I can see why one might come to the conclusion that wine $40+ isn’t worth the price.