With orders of $25 or more, Amazon offers Prime members the Reese's Pieces Peanut Butter Candies 1.53-oz. 18-Pack for $5.29 with free shipping. (Non-members can spend $35 to qualify for free shipping.) That's $0.29 per bag and the best price we've seen. (It's also $6 less than you'd pay in-store locally.)

Note that this item is part of Amazon's "Add-on program" and can only be purchased with an order of $25 or more.