I recently got the Ergotune Supreme as my office chair and am very satisfied by it.
Switching to this chair has made me look forward to sitting in front of my computer to get work done.
With the amount of time I spent in front of the computer to get work done, I think that the price of the chair (about $500) well justifies the value that I received.
For one, there are many places where I can adjust the chair to suit my needs, this makes the chair versatile and good both at times where I want to relax and work.
The company also covers warranty of the chair for up to 12 years, this gives me peace of mind knowing that I am covered in some ways for the next 12 years.