I've never bought into these gaming chair things. You are paying for "gaming" and "gaming brands"
£200 just about buys you a low-mid end budget console chair for an office environment. Eating into that budget for gaming tat simply means you compromise elsewhere. Whether it's the gas charged height adjustment, quality control, fit/finish, materials etc.
I spent a LONG time umming and arring over what to replace my old chair with. I ended up with a Hermon Miller. Yes, pricey. I spend a lot of time using it though, I have the quality, the warranty to back it up and a local agent. Steelcase and the other big name office environment names are work looking into also. Sometimes you can bag some bargains in the second hand market.