as someone who's gone to a uniform school for the past three years, and has had the same uniform since, i've picked up tricks on increasing the longevity of my uniform.
i have two white t-shirts, one navy t-shirt, one long sleeved navy shirt, a cardigan, one beige pair of pants, one navy pair of pants, one navy short, one beige short, and three spirit wear items. i used to have another pair of the beige short and a beige capris but i wound up having them be too small after the first year.
my shorts are from the used uniform sales, and my spirit wear was purchased because I was part of certain clubs and teams. in the past three years, my entire uniform has amounted to about 500$ CAD which is a hefty price.
so how can you increase the longevity of your uniform while decreasing the cost?
1. buy your original uniform used
i did not do this, mainly because i missed the time they were, but this is helpful if you're still growing when you enter the school, or if you simply can't afford to buy and entirely new uniform at once. personally, i had two of the t-shirts, a long sleeve, the cardigan, and two pants, plus a pair of shorts and capris. I later would get the remaining of my uniform from the used uniform sale. if you end up wanting/ being able to purchase a new uniform, it's better to do so after your first year, and by getting the used uniform you can figure out which uniform pieces you'll actually wear.
2. fabric glue for any wear or tear in uniform pants
generally you'll get fabric thinning near the crotch of your uniform bottoms. it'll look like a bunch of the weave has been lost in the same direction (+++ is the usual weave, ||| is how it'll look when worn out). by applying a small amount of fabric glue to the worn area, you'll strengthen the remaining threads, helping it last longer. just be aware that fabric glue dyes slightly darker, so try not to get too much on the regular fabric, and seeing as glue is not made to stretch, if your bottoms have stretch, that area will not stretch with the fabric.
you can consider reinforcing seams with fabric glue if the material is a weave, just make sure to keep it near the actual thread instead of all over the extra fabric. nothing's worse than when a fabric hardened by fabric glue is constantly scratching you.
3. if your school has dark shirts, get them over lighter ones
you can wear them more often without much notice, they don't dirty as easily, and they won't get sweat stains. plus, taking yearbook photos with a dark uniform top looks more professional than a light one in my opinion.
4. actually, fabric glue is your new best friend
i've found the side seams of my uniform tips slowly start ripping from the bottom, so i slather on a little bit of fabric glue to prevent further unraveling of the seam, and since the hem of the shirt is odd, i tuck it in instead of replicating it. also, fabric glue is good if the thread of a button is getting thin. honestly, if you can't sew or don't have the time to, fabric glue.
i got the longest length possible for my pants and it is truly a blessing. while most my friends trimmed off the excess fabric, my hems were a good ten inches of extra fabric folded up within itself. they've had to get new pants every time they grow, i've grown 4 inches since high school started and have only had to let out the hem. yeah, if i grow anymore i'm not going to have much wiggle room, but i graduate in a year, it'll be fine.
6. got a long tear somewhere? if its thin enough, you can sew it closed
if you've got a sewing machine, set it to the longest length of a zig zag stitch you can. then sew the stitch along the hole, backpedaling every so often. voila, hole closed. just make sure you use the same colour thread. in ninth grade, about three months of wearing my uniform, i ripped a hole in the back of my shirt. ironically i was at sewing club when it happened, and i had a tank top underneath, so i was able to fix it then and there. i still wear the shirt today, and no one has even noticed that i had sewn up a hole. if its a slightly larger tear, it's a hand stitch problem. put the single layer in an embroidery hoop, and just stitch back and forth to create a layer of thread that fills the hole. make sure you aren't sewing all the sides of the hole to one another, just that you bridge the gap. (basically if you've got this -> O, you want to make this -> Ø or something similar)
7. get a uniform that fits
fabric shrinks and stretches. have a general idea of what fabric does which. when you purchase the uniform take this into account. if the pants are a little snug but the fabric stretches out after a few washes, then they'll probably fit better than the size up. if the fabric shrinks, and the pants fit loosely, you should be fine. just keep in mind sizing and any growth or shrinkage the fabric will go through.
these are just things i've done i've found work well, let me know your tips and tricks too!