Target offers the Fruit of the Loom Men's Boxer Briefs 7-Pack in Black/Gray, Stripes/Solids, or Assorted Colors for for $11.99 with free shipping. That's $1.71 per pair and the lowest total price we could find for this quantity by $4. (For further comparison, we saw a 5-pack for $12 via in-store pickup in our expired mention from two days ago.) They're available in sizes S to XL.
Stocking up? Add three 7-packs to your cart for $35.97 and apply coupon code "BASICS" to drop the price to $30.97. With free shipping, that's $1.47 per pair and a price low for 21 pairs by $17. Coupon expires August 8.