So, I decided to start looking for something at least a little more comfortable. I think I've just found it.
Here's the link for the chair. It has an original price of $100, with a $20 instant rebate, and a $40 mail-in rebate, for a grand total price of $40.
I figure it should be a huge improvement over my current chair, and it's cheap enough that I won't hate myself if I find a "perfect" chair that I end up buying six months or a year down the road.
Update: Fixed the broken link. Sorry, that's what I get for not testing it. ;-)