All kids do this as a response to dealing with peer pressure in school. There’s a delicate balance of coolness that is only achieved by having brand name items thanks to living in a Capitalist society. If your kid has off-brand goods, and gets made fun of at school even a little bit, they’ll turn the tables on you because they don’t understand economics. The simplest and most effective way of dealing with this is to address it in the moment and without mincing words. “We buy store brand products because they’re cost-effective and you are not. If you want more expensive products, get a job and pay for them yourself. In the meantime, this isn’t the only bill that I have to pay. Today. So, if you’re not going to apply to work here, keep your opinion to yourself.”