Amazon offers the Post Raisin Bran Cereal 20-oz. Box 4-Pack
for $11.77. Add it to your cart via Subscribe & Save and it falls to $10
with free shipping
. At $2.50 per box, that's 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.
Update: Note that this is deal is for Post Raisin Bran, not Kellogg's, as early mentioned.