Our local HD had these in one of the "impulse buy"/gift bins in the main aisle. 4 for $20.
How the gods must chuckle at us poor beasts and our deficient allotment of hands; two is never nearly enough. I've had six of the 6" QuickGrip Mini-Bar Clamps for a number of years. The clamping force is limited, of course, but they have helped even the odds between me and Physics in many a home-repair adventure. Sometimes the jaws aren't quite wide enough though. For my purposes, two for $10 would have been an even better deal, but I'm sure I'll use all four eventually.