Amazon offers the Bob's Red Mill Natural Raw 20-oz. Sunflower Seeds 4-Pack for $12.56. Add if your cart via Subscribe & Save to cut it to $11.93 and bag free shipping. That's about $4 less than you'd pay in local stores. They are purported to be a good source of protein, minerals, and Vitamin E.
Be sure to cancel Subscribe & Save once your order ships to avoid being billed for subsequent shipments.