are there office furniture stores near you? some places have oodles of used furniture that is reasonable/inexpensive - and still in good condition.
It is important to "audition" a chair. What may be comfy for person A might be miserable for person B. I like wheels (get the 5 leg, not the 4 leg - it's less apt to tip over) and adjustable height.
I also vote with the "no arms" on the chair - they get in the way.