One of the seeming oddities of the high end of the fashion world are purses and handbags that can cost well over $1000. (Here's Vogue UK's list of its current hot 100 handbags, prices in pounds.)
From a simple sociobiological perspective, it's hard to explain why any women would compete over something like an expensive purse that straight men simply aren't going to notice. Why not spend the money on getting hair extensions or giant implants or something else that will catch heterosexual men's eyes? So, one theory popular among straight men is that straight women are victims of a gay male conspiracy to brainwash them into competing with each other over stuff that doesn't attract men.
No doubt there is some truth to this, but let's look at it from the perspective of the women who do want to upstage other women by having the newest and most expensive of this season's handbags. Who are they? Typically, they are women with rich husbands. And that means they aren't particularly desperate to hook a new man because the one they've got is paying for their expensive gew-gaws. Moreover, they don't want to associate socially with women desperate to hook a good catch because their own husbands are good catches. So, they prefer to associate with other women who have rich husbands, too.
Women with rich husbands tend to have a competitive streak, which is how they snagged a rich husband in the first place, but they don't want to constantly replay the Darwinian struggle for a mate with the other women in their social circle. They are looking for a hobby they can compete with their peers in without ruining marriages.
So, women with rich husbands will often compete over things like handbags, a contest to impress other rich women and gay men, but not to arouse their friends' husbands into breaking up their marriages. It's a cartel with rules to keep the competition from getting out of hand.
It's like how a construction worker might go to Las Vegas and win or lose $20,000 while a the rich husband of one of these women is more likely to go to his golf club and win or lose a (largely symbolic) $20 bet on a golf game. As Freud suggested, the higher bourgeois classes tend to have more sublimated, less destructive hobbies.