Put your money where you spend your time. Don't spend money on something if you won't be using it.
You spend a lot of time sleeping, so get a nice, comfortable mattress.
Spend a lot of time on your feet at work? Get durable, comfortable shoes/boots, and maybe some nice insoles so you don't limp back to your car from pain.
Spend a lot of time playing a F2P video game? Go ahead and buy that DLC or cosmetic item to make it more fun, and support the devs to keep the game going.
The list can go on, but before any non-trivial purchase, I ask myself how much time I will spend using it.
I like to measure costs in dollars per hour, similar to this. So what if that hobby item is 400 dollars. How many hundreds of hours will you get enjoying it? So like, a dollar an hour.
A movie you don't care about seeing? 20 dollars for 2 hours. Maybe hold off.
Agreed and agreed. But an addendum regarding mattresses: No matter what the salespeople tell you, most mattresses with pocketed coil springs are pretty much the same apart from hardness, especially with a compensating mattress topper. Just get one that feels right to you, definitely don't think that more expensive=better, mattress-wise.
More money advice: Most things come in two tiers worth purchasing: "nice" and "wow".
"Nice" are the things experts deem good enough, or clothes-wise ones that you can see yourself actually wearing across multiple years, both durability- and appearance-wise. Affordable, and you like them. A useable placeholder, if you will.
"Wow" are the things that you've been steadily dreaming of for years, or ones that catch your eye even if you weren't looking. "Buy it for life" stuff. Solid whole wood furniture, that teapot or coffee maker you've been dreaming of. A designer winter coat that only costs 20 times your old one. 🫣 On these you look at the price tag after; you want it, you get it, and if it breaks, you repair it. If it's affordable, or if you find more than one of these every 1-3 years, consider yourself very lucky.
Nothing below "nice" is worth getting, and very few things between "nice" and "wow" are worth getting.
I ordered a 10€ "Skmei" watch from Aliexpress and it died in a year. My cousin buys ~30€ casio watches and they last at least 5 years of abuse.
Cheap Redmi phones have half the processing power of a top end midranger and will not decently survive years of planned obsolescence. I only have a Redmi (4x from their decent times) because I got it for free from my dad. It's a decent phone, but performance is terrible so they aren't worth paying for from the longevity standpoint, but if you need a temporary phone they are decent.
I invested in an Areon chair and have zero regrets. Best decision I ever made. I work as a software engineer, and also game in my spare time. So sitting around is a lot of what I do unfortunately.
Can confirm on the shoes. Whatever else needs cut back, as long as you can afford rent and food and gas to get to work, buy good quality shoes. Not all expensive shoes are good, but good shoes are not cheap. Second hand good shoes that are your size are very very rare. Upgrading insoles can get you by for a while, but there's nothing like good quality shoes.