Amazon has the 40-Pack Lay's Regular & Kettle Potato Chips Variety Pack on sale for $18 - 15% off coupon (check "Save an extra" box, eligible on first S&S order for this product) - 5% off with Subscribe & Save (can cancel anytime) = $14 with free shipping on $35+ or with Prime. Roughly 36 cents per bag. 

Includes (6) Kettle Cooked Jalapeno, (6) Kettle Cooked Original, (6) Kettle Cooked Mesquite BBQ, (6) Salt & Vinegar, (8) Classic, and (8) Sour Cream & Onion