I don’t have kids, so I can’t give the OP advice on how to raise them.
But I was a kid and have some experience with this very issue. So here’s how I saw it from the kid’s perspective.
I grew up in the 80s and moved from my mom’s house to my dad’s about 1980. My stepmom had five kids who were all about 10-ish years older than I. When I hit middle school, everyone who wasn’t getting beaten up on the daily wore Jordache jeans, the one and only Nike (I think there was only a blue stripe at first, then they came out with the red stripe later), and Izod polo shirts. That was it: standard de rigeur uniform for middle school and high school kids at the time.
I begged and begged and begged and begged and begged and begged for just one pair of Jordache jeans (easily twice the price of Levi’s or non-designer jeans), buuuuut nope. In fact, my stepmom told me I could save up my money (I was 12) and in the meantime, there were some old jeans in storage of my older stepsisters’ that I could wear if I needed jeans. Reminding you that those sisters were a minimum of 10 years older than me, that meant I was being offered low-waisted bellbottoms to wear instead of the trendy high-waisted cropped ankle jean that was the rage at the time.
So I got beat up on the daily. In gym class, in choir, on the walk on the way home. Constant abuse.
Well, I was 12, and saving up babysitting money (there was no allowance and I did not ever receive money for birthdays or Christmas) to $50 for a pair of jeans at $1 an hour was going to take about 50 hours of babysitting, which, at twelve, was going to take me a few months. (When I was 16, I could have come up with $50 within a week.) So I skipped lunch every day and ate one meal a day, and that still took me 50 days to save up enough, which is like, a third of the school year. Eventually, I got in trouble for skipping lunch – because my dad knew I never ate breakfast – but I’m here to testify that being grounded for a week for not eating was completely and totally worth having the “right” jeans to wear to school. That is fucked up on so many levels, I can’t even.
Note the peer pressure to fit in was not quite as harsh on my older sister who was in high school.
I learned how to sew because I learned (quickly) how to peg the seams on those bellbottoms so at least the leg part was closer to in-style.
Finally, my best friend told me she had a pair that “didn’t fit right” so she gave them to me (with her mom’s permission). I suspect that she just got her mom to buy her another pair just like those so I could have that one pair of jeans that would keep me from getting the beat down every day on our walk home from school. (Which was like one mile, through crack-infested neighborhoods, with zero adults paying any attention at all.)
So, things are different now. And being bullied only because my clothes weren’t in style was only restricted to middle school. By the time I got to high school, Levi 501s were acceptable and affordable so were also stepmother-approved. I could get away with knock off polos and shoes other than Nikes, but the jeans you wore mattered, but only until high school and then everyone went back to not giving a damn. And there was less “pick on the poor kid” in high school, mostly because the poor kids were all banded together in the vocational classes and ran in packs.
Your kids may not be experiencing bullying to that same degree and it’s possible they can get away with knock off clothing that’s close. But my suggestion would be to ravage the used clothing stores and places like Goodwill for name-brand stuff that’s a little worn, but way cheaper, and at least has the right label. That and I do advocate asking the kid to save up his own money for a thing he wants, but only if that kid has a revenue stream, like an allowance or birthday money or a paper route or something.
My primary message is that the laser focus on clothing labels doesn’t last that long socially speaking. And if I had a kid and it was my kid, I’d be inclined to A) Try to find used clothing for cheap and B) Try to get the kid suited up according to the school “uniform,” even if that uniform happens to be a designer shoe or whatever.
Now my sister and I had/have self-esteem issues from a whole laundry list of other things, but my parents’ hard-ass stance on this did not help matters. My dad later expressed regret to my sister that he didn’t try to compromise a little bit on the designer clothing thing, seeing as how it was only important to us for a couple years, but the self-esteem damage lasted decades.