Harbor Freight has two sizes and two models in each size of the clamps that you screw to a jig and then snap shut on sale. The smaller ones are 2.99 and the next larger size is 3.99. Not in the flyer, but marked in our local store was an even larger size that was marked Closeout @ 4.99.
I would not have bought these without seeing them, but the best I can tell, they appear to be exactly the same as the ones I have bought previously at Wood Craft and Rockler (that I paid a LOT more money for). I was convinced enough that I bought about 14 of them. IIRC, the Sale Flyer showing these items says this sale ends March 21, so IF you need some for present or future jigs, check them out.
One of the Flyers also showed some Rare earth magnets for nearly nothing, (maybe 1.79 for 5 or 6), But......our store didn't have any, so I can't say what size or quality they were.
The Magnetic Bases for dial indicators, (to be used in featherboard or other type jigs as discussed recently in this forum), are also on sale again for 8.66 now.
Note: The difference in the two models of the snapdown clamps that are available in each size is that one type locks by "Lifting" the handle (or whatever you call it), and the other model locks by pressing the handle down.
Cheers to all, and Have fun shopping
EDITED, because I Finally remembered those clamps are called TOGGLE CLAMPS.
(The "Toggle" just Would NOT Come earlier).