Small and mighty! The hand vise can be a great tool in a pinch. It can serve as an adjustable wrench or just the right clamp to hold that object you need to get at with a dremel tool.
I have been know to do a little gunsmithing here and there, and the hand vise can be valuable here as well. Need to do some trigger polishing, a hand vise can hold parts while you polish away.
You can find a range of prices for quality vintage hand vises. Starrett 86A hand vise (shown below) is considered the Cadillac and can bring $250 – $400 depending on condition and if it has the cool table mount accessory.
You may also come across the Bridge City Tool Works hand vise, most of them are considered collectible and never really leave their fancy box.
Probably the most affordable and quality option is Millers Falls with examples selling for $75 – $150 typically.
