I’ve bought mine PoP coats for years. Well, my eldest 2 are too big now, sadly, but my youngest still wears them.
They are expensive (although do good sales), but last really well, and are roomy. Eg I bought my eldest one that she wore for over 2 years, then the next one wore it for 3 more. It’s now waiting for my youngest to grow into it, and he’ll wear it for at least 2 years I expect. 7 years wear out of an £80 spend is not at all bad, if you ask me, and it’ll still be good enough to pass on or sell.
Dd2 had a PoP coat for her school coat for 2 1/2 years - she said it’s the warmest she’s ever been at school. She’s now too big for PoP, and so has a different brand, and she says it’s neither as comfortable nor as warm/water/wind proof. It’s good enough, but not as good. She isn’t particularly into labels, so it isn’t that it didn’t cost as much, or isn’t cool enough, it just isn’t as comfortable or as warm.
Ds is still wearing PoP, and has a good few years of hand me downs left, and is happy with that. He too says his home coats are much warmer and more comfortable than his school coat (has to be a branded one, but it’s roughly equivalent to M&S storm wear), and definitely more wind proof.
I always went for something that I absolutely knew was more than enough for British winters - all 3 dc have communication disorders, and so when they were young were unable to tell me if they were uncomfortable. The habit just stayed, but as I said before, I didn’t need to buy each child a new one each year, so the cost saving there has been quite large too.