Meritline offers this 16-Foot Right-Angle Jack Replacement Audio Cable for Headphones for $4.99. Coupon code "MLCKY22GNL1" cuts it to $1.49. With free shipping, that's the lowest total price we could find by $3. (It's also tied with our February mention of a 4-foot cable.) While the product description says this cable is for Beats Audio headphones specifically, it appears that it could be used with most other headphones. Coupon expires after 300 uses.
Expect this item to take two to three weeks to arrive.