Poor buying when things expensive they are expert buying top in everything and FOMO in also the middle class are expert on buying highest prices and not just buying they buy it with credit.
Rich buys when something is with good price low price poor buys just to spend money.
Middle class behave like poor too they buying expensive.
Poor people mainly buy products to meet their needs, but they never check the quality of the products. Middle class people don't have the budget to check the quality of products, and they don't buy even low-quality products. But those who are high-class basically check the quality of the product and then purchase it, regardless of the price of others.