Sunsella via Amazon offers the Sunsella Buddy Boxes 4-Pack in Multicolor for $13.79 with free shipping. (Non-members can spend $49 to qualify for free shipping; otherwise, shipping costs $6.78.) That's $6 off list and the lowest total price we could find. Each container features three compartments and is microwave-, dishwasher-, and freezer-safe.
Of note, Grey is available for $12.95.