Amazon offers the Bob's Red Mill White Popcorn 27-oz. Bag 4-Pack for $11.80. Add it to your cart via Subscribe & Save to drop the price to $11.21 and bag free shipping. That's tied with our January mention and the lowest total price we could find by $6, although most merchants charge $21 or more. It's gluten-free.
Be sure to cancel your subscription after receiving your item to avoid being billed for subsequent shipments.