I've never used a chair that I personally found decent for less than $100. Most of the time I buy $150 chairs every few years. My last chair was $149.99 and it lasted from 1999 to present and was semi-retired due to the padding basically being worn down in many spots. I am now using a $150 leather chair that I got from Sam's. It's comfortable and badass looking.
$40 - $60? then yah, staples or office depot is fine, lol. They usually have your standard office chair for $25, and your "executive" knockoff office chair for $50. Here's an informative thread about chairs: