I got an office chair that supposedly was $1000USD new.. it was many years used, but I really liked that chair. It had steel construction, swivel and almost no "rocker" tilt, wide base seat almost flat but with a seat cover that was just right.. it was square box'y basically .. shorter answer, do not use a cheap chair really.
Tried Herman Miller. To me it was very uncomfortable and I could feel the mesh and lining. Went for another type of chair that is marketed as ergonomic. It is polyster and has all the support you need, especially for tall people. It's not very soft but extremely good for your back.
Especially now, there's warehouses full of them. If you're comfortable bargaining you can even get them cheaper since demand isn't that high. Delivery might be a reach, but they'll often do it for $20-$40 if they have a delivery near you.
It isn't even splurging, just spending some time looking through Craigslist or Facebook Marketplace.
Everyone reading this: Take care of your back!