13Deals offers the officially licensed NFL Equipment Men's Moisture Wicking No Show or Ankle Socks in Black or White for $4.99. Coupon code "NFLGEAR" drops the price to $3.29. With free shipping, that's $7 off and the lowest total price we could find. They're available in sizes 9 to 15, although not in all size/style/color combinations.
Need more? Add three pairs to your cart and apply the coupon above to drop the price to $6.59 ($2.20 per pair), or add six pairs for $9.86 ($1.64 per pair) after coupon.