On the other hand, its a good idea to bring your own lunch, which saves a lot of money over eating out every day.
Its easy to find a cloth bag, mini-cooler, or lunch box to carry the complete meal in, but you still need something to keep your sandwich from falling apart inside your lunch box.
You could wash out and reuse the same ziplock bag over and over, but they aren't easy to wash or dry, and they aren't that durable.
A few companies are selling reusable sandwich holders, but they cost $10 or more.
You can make your own for free in just a few minutes!
-a 16" x 16" (or bigger) piece of strong plastic film
-a 16" x 16" (or bigger) piece of cloth
-pencil or pen and chalk or marker
-a sewing machine or needle and thread
-velcro (could substitute a snap, button, or other fastener)