With orders of $25 or more, Amazon offers the Rubbermaid Lunch Blox Sandwich Set for $6.39 with free shipping. (Target charges the same.) That's $2 under our May mention and the lowest price we could find by $7. Designed to save spaces in lunch bags, these reusable containers are BPA free and dishwasher-, microwave-, and freezer-safe.

Note: This item is part of Amazon's "add-on" program and can only be purchased with orders of $25 or more.