Just a quick comparison:

4x4 12ply 100 bx
Buyemp.com $6.44 Dukal
mfasco.com $6.94 Dukal
Redflare.com $17.00 Swift
BPMedical.com n/a
Fieldtex.com $8.75 Dynarex

For the life of me I couldn't find 4x4's on the BPMedical site.

Redflare does sell these indivudally, everybody else sells them by the box.The rightmost column is the brand name.

Shipping costs and other product selection varies.

Not an endorsement, just geting some time away from a boring task at the office...
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In a crisis one does not rise to one's level of expectations but rather falls to one's level of training.