I needed a mini-tubing cutter, to cut off less than a half inch underneath the sink. Happened to go to Pep Boys after HD.
Home Depot, 16 dollars.
Pep Boys, 7 dollars.
The Pep Boys one was hard to tighten, even though the knob is well knurled and the screw seemed to be lubricated already. I've never used any other brand, so don't know if it would be easier. And I'll probably never do this again.
But it still did a good job of cutting the tube.