You might want to take a look in your local Curry's/PC World, they have the Arozzi Vernazza on sale at £250, I have one and I absolutely love it. I did look at the Nitro Concepts chairs but they appear to have a centre tilt mechanism which, in my opinion, is far inferior to the knee tilt mechanisms on the "higher-end" chairs. I bought mine direct from Arozzi because they didn't have one in my local PC World and it cost me £290 with a 10% affiliate code I found on Youtube, but it's worth every penny.