I note the local catholic school has very smart uniform, however all parents have the option, they don't have to send children to a faith school so they can require expensive uniforms. But it also labels them as catholic not sure this is a good idea, it could make them a target.
Cost of uniform can be debated, I know my grand daughters have school badges which my daughter has embroidered onto their cloths and has not bought them from local shop, however the sewing machine required to embroider these cost well over £1000 so not some thing every mother could do.
Requiring grey trousers, white shirt, black shoes, grey socks and a brown blazer is I suppose OK, however as soon as that becomes a blazer from local high street store with a badge on it, then that over steps the mark. I remember one guy at school had an odd tie, he say it was from Dorchester Dayschool however sure really double diamond beer. But secondary school colours were same where I lived to grammar school colours where I went on holiday so would wear part of school uniform on holiday.
Kings school and Queens school (latter for girls not odd boys) in Chester having a Uniform to me is no problem, it does not identify faith all it says is my parents have money, and can afford to give me a private education. Ysgol Glanrafon school uniform I suppose shows the shop keepers what language they can use, if wearing that then they will speak Welsh, but all it would need is a school tie, it does not have to be anything more.