Office chair recommendations?

I’m looking at getting a new office chair. I’ve just gone through my 3rd ~$150 one from Staples/OfficeMax/Office Depot in as many years. I spend an awful lot of time on my computer as an IT student at home.

I was looking at the following:
Steelcase – Leap
Knoll – Life
Herman Miller – Aeron or Mirra.
Neutral Posture – Balance

I’m looking at something less than $400 and am aware the only way I’ll get any of the above are used which also isn’t a problem. The only other caveat is that it must have armrests.

If anyone has any experiences with the above, or found one they liked more, I’d love to hear your recommendations. Also, if you have a solid recommendation to a legit online store with great used prices you’re my hero.