With orders of $25 or more, Amazon offers the Pringles 1.41-oz. Small Stacks 12-Pack in Sour Cream and Onion for $4.22. Clip the 25% off coupon on the product page to drop the price to $3.16. With free shipping (non-members can spend $35 to qualify for free shipping), that's $0.26 per canister and the lowest total price we could find for the quantity by $13.

Note that this item is part of Amazon's "Add-on program" and can only be purchased with an order of $25 or more.