ElectOtronics is selling the old standard Panavise #301 for only $31.79. I used to be skeptical about the utility of the Panavise, but now I use it for all sorts of delicate jobs that require the multi-axis positioning and gentle grip — filing small parts, tapping, etc. AVToybox lists it for an even lower price, but their cart system seems broken, which is annoying.
I like to attach one of these to the side of my rolling tool cart — it’s great for car work or doubling as a soldering iron holder. Though this may not be a recommended use, it does work well.