I was also looking for HM Aeron but couldn't afford it even used.
I settled for a brand new WorkPro chair, full name copied below. I have been using it for a year and its been holding up great. I use Aeron at work and this one at home. I would say this would come 85% closer to Aeron with 1/4th price, so pretty good deal. The arm rest is not as adjustable as Aeron but the overall chair is as comfortable as Aeron. Also, I bought this on a deal for around $190 I think.
WorkPro® Quantum 9000 Mesh Multifunction Ergonomic Mid-Back Chair, Black
As others have said, gaming chairs are a scam. Whatever chair you get, I'd have it be a mesh one. I got this chair at Office Max probably 6 years ago or so, use it 4-8 hours a day, and it looks/functions like the day I got it. It was about $100 cheaper back then but it's an amazing chair.
https://www.amazon.com/WorkPro-Quantum-Ergonomic-Mid-Back-Chair/dp/B00JRE37Z0
WorkPro Quantum 9000 Series Ergonomic Mid-Back Mesh/Mesh Chair, Black on Amazon. It’s basically a Hermann Miller knockoff but I’ve had it for over 10 years and it’s been awesome. WorkPro® Quantum 9000 Series Ergonomic Mid-Back Mesh/Mesh Chair, Black https://www.amazon.com/dp/B00JRE37Z0/ref=cm_sw_r_cp_api_i_WVDM9T9MBNE8K12RBD11?_encoding=UTF8&psc=1
I have a WorkPro Quantum 9000 which is basically a knock-off Hermin Miller for $400-500 and I've been loving it so far. Won't win any points for aesthetics (unless you like the boring office look), but it's super comfortable to sit in alllll day long, and it's mesh so you won't get swamp ass in warmer weather
Love the setup dude! My personal recommendation for a chair. I've had mine for several months now and had some back injuries in the past. I love this chair and can sit in it as long as I want without any pain.
It was recommended by a streamer I watch who regularly sits in their chair for several hours a day. It's expensive but worth it for the comfort and support.
*slow clap*
EDIT: While I'm here, Im betting you already got one, but I'll add my advice.
I use an Aeron at my work. I absolutely hate it. There's plenty of things that you can adjust, but it seems like all of these things can't be set anywhere near as precisely as I would hope. The knobs make it look as if you could adjust things to minute settings, but really it's always more like four positions per knob.
The sturdy seat is supportive, but not comfortable. I understand the idea is that you "need" to have good posture, but the aeron 100% forces you into one... position... everything else is uncomfortable.
I'm sure a chair that allows you to easily, slightly adjust positioning is actually better for you. If your body wants to lean back a certain way, or sink a certain part of your body somewhere, you probably should, and not stay motionless for hours at a time.
That being said, I am putting some serious thought into the Realspace PRO Quantum 9000 with the cushy fabric seat.
The Markus was ok, but not as adjustable as I'd hope. I'm particularly a fan of adjustable arm rests, which the markus lacks. (Real shame, with how modular a lot of ikea stuff is, you'd think they'd just sell them, right?)
I'm very interested in the gaming/racing chairs. In vehicles, I'm always very comfy in those chairs. I've read that the DX racer chairs are all pretty stuff, and not really "comfy in a plush way" as they are good at making you be alert. You aren't uncomfortable, but you aren't actually particularly comfortable.
I wish I could actually sit in each of the DX racer chairs before making a decision. If I found I liked none of those, I would then just go for the Quantum 9000. (Also, avoid buying this one used, as there was a recall for a dangerous breaking part in 2009. So just... buy it new.)
It's a Workpro Quantum 9000 chair with the arms taken off and new casters put on.
https://www.amazon.com/WorkPro-Quantum-Ergonomic-Mid-Back-Chair/dp/B00JRE37Z0
As much as I would like an Aeron, the price was just too steep. I ended up going with this kind of knock off for $400 but have been extremely happy with it
https://www.amazon.com/dp/B00JRE37Z0/ref=cm_sw_r_cp_api_glt_i_JN2Z7QYMA84W3ZATVHQ6
Looks like a knockoff of the WorkPro Quantum 9000
https://www.amazon.com/WorkPro-Quantum-Ergonomic-Mid-Back-Chair/dp/B00JRE37Z0
Looks very similar, but not the same chair. You can see the tilt tension adjustment is different.
I work on campus and have been remote since 2019. took my HM home and as I looked at going back went looking for something to replace the HM UIUC owns.
Tried this, and would up buying a second for my wife.
https://www.amazon.com/gp/product/B00JRE37Z0
These are solid. simple to assemble and can easily leave the arms on or off as you choose. Not cheap, but 1/3 the price of retail HM chairs.
I got a WorkPro Quantum 9000 a bit less than a year ago and have been pretty happy with it. We also have a Herman Miller Mirra at home to compare to. I would call them equivalent. They each have subtle differences and each has their small pluses and minuses.
https://www.amazon.com/WorkPro-Quantum-Ergonomic-Mid-Back-Chair/dp/B00JRE37Z0
It's a Workpro Quantum 9000 chair with the arms taken off and new casters put on.
https://www.amazon.com/WorkPro-Quantum-Ergonomic-Mid-Back-Chair/dp/B00JRE37Z0
I have one of these. I got it for under $300 and it's been the best chair I've ever had.
WorkPro Quantum 9000
https://www.amazon.com/gp/product/B00JRE37Z0/
Check it out and see what you think. I have owned one for over a year now and I love it. It has held up very well. No complaints yet. I'll update again in another year perhaps?