My local BB&B had K cups for about $0.15. They are marked down as clearance, so it might be store-specific. Box of 42. Regular price $19.99. Marked down to $9.99. Take off 20%, makes it $7.99. Then, remember that you bought $25 GC for $20 via Amex, so effective price is $6.40, which is $0.152.
Expiry date is 5/2018.