You have no idea what you would do if you were poor until you are poor. And not intermittently poor or formerly not-poor, but born poor, expected to be poor and treated by bureaucracies, gatekeepers and well-meaning respectability authorities as inherently poor. Then, and only then, will you understand the relative value of a ridiculous status symbol to someone who intuits that they cannot afford to not have it.
I still think that for most people, buying a $2,500 handbag is ridiculous to say the least. It's more about the attitude that comes with luxury items than anything else. The reason her mother got things done was not just because she wore expensive clothes or 'talked like white folks', but because she convinced the clerk that she was someone worth listening to. Charisma, infleunced by her clothes but not caused by it.
Often, nice clothes will give you confidence, and there are enough people around who think they need expensive items to give them confidence. It's the same reason outbound call center workers sometimes have to wear suits, even though the customer will never see them.
But that doesn't mean it's a smart move for poor people to invest in $1000 suits if they can achieve nearly the same with a better, stronger body language and regular, neat clothes. It can be taught, not just bought.