I sold cartoon strips in 5th grade -- thank you Mr. BT for a great year. He had our class create our own society (history, laws, money) and we lived in it for the half hour or so after lunch for a semester. We could sell and buy things, but only things we made ourselves.
It is true I was paid in "Bones" (I didn't come up with the name, but I did design the money -- green triangles with the words written in bone shape... (dittoed not copied back then of course! Ahh, purple ink.)
I still have some Bones all these years later.