Amazon.com offers this Post Raisin Bran Cereal 47-oz. Box 2-Pack
for $8.93. Order via Subscribe & Save and it falls to $7.59
with free shipping
. At $3.80 per box, that's $15 off and the lowest total price we could find for this cereal in this quantity.
Of note, be sure to cancel Subscribe & Save after your order ships or you'll be billed for subsequent shipments at whatever price Amazon charges then.