too bad it's sold out everywhere, any other recommendation with similar price range?

Hi, is anyone aware of any ergonomic chair with replaceable seat?

I tried several chairs (price range from 500+ to 1000+) over the years and all of the chairs 1st problem is their cushion gets thinner and harder when you sit more. Eventually it's feel like you are sitting on rock. So it will be great if we can replace the sitting cushion once in a while to let the chair last longer.

great, thanks