Poor people are concerned with material things because they are in need of it or should I say obsessed, poverty is a state of mind so if you give a person with this mindset some millions they will end up lavishing it and buying expensive things. I heard mark Zuckerberg was in Nigeria few years back and he was spotted somewhere in Lagos putting on a regular t-shirt and a jean and people consider it to be an average look but he's a billionaire, but it's funny how someone with just 1 million naira in Nigeria has so many shiny outfits just to impress others
The mentality is the key here, the resources that we have at our disposal are limited and how we decide to use them will dictate if we improve our lives with them or not, someone spending most of their disposable income in clothes and other luxuries will most likely never progress in life, while someone that started on the same conditions but used their money to prepare themselves and invest, will soon enough find themselves with more money than what they know what to do with.