High end chair worth it?

Perhaps a stupid question to ask here but hoping to get some additional information from the experts here. I'm in need of a decent office chair to work from home and I'd also like to use it casually every now and then since my space is limited.

Steelcase in Europe has a promotion for -20% on the Gesture making it around 900 Euro and that seems to be quite a good deal. However, there is no place to see them live or test them anywhere around here.

I'm still in doubt tho, as it is still a lot of money for a chair. The chair I'm using at my office is from a reputable brand and it sits fine without causing discomfort but is not great looking. That one sells somewhere between 200-300 euro refurbished (think they only renew the fabrics). Probably could find it around 75-100 Euro's used in alright shape. This seems like a decent option that would save me a lot of money.

On the other hand a new steelcase chair would come with excellent warranty. A more high end chair from the local brand would still set me back ~700 euro but only have a 2 year warranty. If I'm spending that much money I'd prefer the steelcase. Although I could test the other one and have it delivered tomorrow.

Other options would be a Herman Miller Mirra 2 as it can be found the same price as the Gesture (I think the gesture is better looking tho). Or a Herman Miller Sayl which would be new around 600 Euro I think. Since I'm not tall it would fit me based on what I read but not everyone seems to be positive about that one either. Aeron and Leap are not an option due to the budget I might be willing to spend.

Question is would I really benefit from a very fancy Steelcase chair (or Herman Miller) or would I end up paying 900 euros to only realize it's just a slightly better chair than the one I could have picked up used? Would it even be a better chair if my current office chair also can be adjusted in many ways and does not cause me any discomfort? Did anyone feel underwhelmed about their high end chair or is it really worth the money when compared to a decent mid-range option?