We spend 12 or even more hours a day in our office chairs. Now, different medicial doctors say that our sedentary life is killing us. Sitting is killing us.
Well, at least do your back and hips a favor. If you work from home a 30 dollar IKEA or WalMart chair is completely insane. Spend the money to get a good comfortable chair that FITS YOUR BUTT. Go to office stores and test drive as many chairs as you can find. See what feels good. Once you pick a chair then we can talk upgrades.
One thing even on expensive chairs, the wheels suck. I always buy upgraded wheels that look like roller blade wheels. Good bearings, roll nicer, better on carpet, etc. I end up with $20 or so depending on the sale price in a set of upgraded wheels.
Do yourself the favor to look at this a it is your 12 hour a day or more home.