Great to see more offline map projects. Is this any different than Organic Maps currently? The about page indicated this project is a continuation of Organic Maps due to issues with that project, not sure if there are new features or if it will be the main project going forward.
Le Laboureur work shirts can be under $150 at some stores. They are a different style though and have been difficult to find in stock online.
I only recently ordered some so have no direct experience. The durability of the fabric and quality of construction are substantial from everything I've read.
It's worth asking to use a bag you've brought. I do that all the time and businesses don't mind at all. Many are actually surprised and think it's a great idea.
For less planned purchases, I find it pretty easy to keep a bag in backpacks, jackets, etc. for ad hoc purchases (or carrying anything generally) to forgo one time use bags. The ones I use for everything are lightweight and foldable, and can easily fit in a pocket.
In my seventh grade history/social sciences class two of our main projects were to draw physical maps (no political borders) of Africa and North America. They were drawn on blank paper a few feet in each direction, and students would generally draw a faint grid to help with accuracy.
We were graded on the number of physical features included, and how accurately the coasts, rivers, mountains, etc. were drawn.
I wonder if anyone still teaches with similar projects. It was a great way to learn in detail about the surface of the Earth.