Through midnight tonight, Giant Eagle has Coke 2-liters on sale for $0.79 apiece.
AND they have a promotion wherein if you buy ten selected Coca-Cola, Nabisco, or Kraft products, you get a coupon for $7 off your next shopping trip. This promotion includes Coke 2-liters.
So you can buy ten 2-liters of soda for an amortized cost of about $1.00.
I've done this twice today.