Just bought a ton of staples which were on sale from $3.99 per pack to $0.92 or even some at $0.72 when I purchased.
Sizes 1/4" - 9/16" Narrow, wide, chisel, divergent tips, manual, electric compatible all sorts.
I personally get the best use out of the chisel point ones, using both my manual arrow and dewalt stapler (don't have pneumatic or electric).
Make sure you check the compatibility shown in each item.
Link to all they have:
You can combo with coupons or points or gift cards. I personally had $22 in "freepoints cash" their new mimic so I got 24 packs for 8 cents out of pocket.