This reminds me about signalling theories in animal mating (reminder: we are animals too). For example, the idea about the peacock's tail being a good signal p

This reminds me about signalling theories in animal mating (reminder: we are animals too). For example, the idea about the peacock's tail being a good signal precisely because it serves no other purpose (and in fact can be a burden!). It signals that the individual is so well off, he can afford wasting resources on such a "useless" ornament. According to this story, trading actual goods for a useless ornament would be a strong social signal that you are so rich, you can afford to lose actual resources in exchange for mere ornaments.