I think it's silly and wasteful, but I don't think it's difficult to understand. Modern aristocrats have so much money that the cost doesn't matter at all, and they probably get it for free in the hope that they'd be seen wearing it by all the wannabes who can afford it.

But even if they pay full price and pick it for some dumb reason like the color or because it's soft, with the average net worth growth these people see in a month or year, any time spent buying the thing would be far more valuable (or they would passively make far more money) than the cost of the shirt.

But silly things like transactions and opening packages of free overpriced fashion are for underlings to handle anyway.