Those who do not have the resources to buy something that is beyond their financial means should not buy it. If they are aware of their financial means and still really want a certain item, like an iPhone, for example (it may seem like something modest to many, but here in Brazil it is very expensive), that same person will buy it in installments, and that is okay, they did what they could.

This is not what defines rich or poor, it is more complex. What is not acceptable is for a person to stop buying the basics for their family just to have something material. That is not being poor, it is being stupid.