Staples has Keurig K-Cup Eight O'Clock 18 ct boxes on sale for $9.99. (Original, Hazelnut, Columbian, Dark Italian)
Buy 10 boxes, for $99.90
Apply coupon code 64380, which will lower the price to $79.92
Apply coupon code 56515, which will lower the price to $59.92
$59.92 /180 = $.33/K-Cup (rounded down)
For the $11.99 boxes:
Buy 8 boxes, for $95.92.
Apply coupon code 64380, which will lower the price to $76.74
Apply coupon code 56515, which will lower the price to $56.74
$56.74/144=$.39/K-Cup (rounded down)