I've been rediscovering the joys of the ball-point pen, a much-underrated medium. I've written and drawn with pens costing hundreds of dollars, and disposable pens that cost just a couple of bucks, and as far as I can tell there's no particular reason to spend a lot of money on a ball-point pen except to display your wealth.
* This turns out not to be entirely correct. My Parker-style refillable ball-point has kept going smoothly where the el-cheapo disposable pen started to stutter and glom up, so it looks like it might actually be worth spending a little more than $4 on a pen. (It also feels nicer in the hand than the extremely lightweight plastic jobbies).