And here I am, happy with whatever chair that needs a little TLC that I literally find for free on the side of the road, trying to make sense of this thread promoting the purchase of chairs that cost as much used as I would very seriously consider spending on a used car. It seems to me that good posture should be your own responsibility, not that of some fancy chair. At home I have some cheap mesh chair with literally not back support at all above right below my shoulders, partly since that's all there's room for where it is. My posture is still quite good, because If I start hunching, slumping, etc, I notice and adjust my behavior.
A well made chair lasts a very very long time, and also helps you to maintain good posture without having to monitor yourself all the time. You can maintain the best posture on earth, but if you're sitting on a cement block or something, your ass is still going to hurt. A chair purchase is arguably more important than any of the pricey keyboard purchases anyone makes in this hobby, and a lot of the time cheaper.
Not to mention lots of these chairs have warranties that extend well past the time of you purchasing them used, that are still actionable even by you as a second owner.
That cheap mesh chair I use at home I got brand new for $70 at Ace Hardware ... to accompany my very first desktop computer, so that was probably around ... 2005? The entirety of its frame is made out of steel, down to the base. Only the wheels are plastic. I imagine it will easily last me another 15+ years, and well beyond, even if the fabric on the armrests is beginning to come undone.
The chair I'm currently seated in is a Broyhill I picked up at Goodwill for $15. The bolts holding the arms to the backrest and seat were loose, so I had to remove the cloth on the bottom of the chair to permanently resolve that problem with some loctite. The base was originally plastic, and somebody, without my knowledge, obviously abused the thing at work while I was not present. I showed up one day and the base was broken where the stem of a wheel entered it. I figured, why not
permanently fix that problem as well, so I bought a $20 solid aluminum base on Amazon. Soon after the wheel event, the gas cylinder also failed, probably as a result of the same prior abuse. This again was seen by me as an opportunity. I am relatively tall, most of that height being really long legs, where I literally cannot rest my legs flat on most adjustable chairs even with the height adjusted as high as it will go. I figured, why not resolve that problem as well? I found a taller cylinder than average one for something like $15-20 with very good reviews, and carefully applied some lithium grease when I replaced it so that it spins with almost no friction at all. I had also already had awesome roller blade wheels ($30 investment) installed. In short, I basically have a fully customized/reinforced/personalized chair with a still-supple, comfortable seat and supportive back with the total investment cost of a cool $85, give or take $5-10.
I have seen this same chair on the side of the road before, although I was at work, driving between locations, so I failed to pick it up.
Another chair that's also at this very location at the moment is one of those nice mesh adjustable chairs that has something like 4 or 5 different levers for adjustment, and adjustable armrests. I found it on the side of the road ... for free, because there was a chunk missing from the original rubber armrest on one side. A $20 purchase from Amazon later ... good as new. I also put roller blade wheels on that chair, and it is also fantastically comfortable.
Both of these chairs have lasted me roughly 5+ years, thus far, and wild highschoolers are usually horsing around in the mesh one.