Amazon offers the Clif Kid Organic ZBar 1.27-oz. Bar 18-Pack in Chocolate Brownie or Chocolate Chip for $10.50. Add it to your cart via Subscribe & Save to drop the price to $9.97 at final checkout. With free shipping, that's 55 cents per bar and the lowest total price we could find by $3.
Note: Be sure to cancel Subscribe & Save once your order ships to avoid being billed for subsequent shipments.