In the first case, I ate a lunch, did not create any other economy activity
No? You sure about that? What did you have? It cost $10, so if you avoided economic activity, it must have all been home-grown. Which means that $10 must be the pro-rated "labor" cost. How much are you "paying" yourself to do all that work?
Even a tomato sandwich is a lot of work, if you did not create any other economic activity thereby. You have to grow the tomatoes, and the wheat for the bread, maintain the cows and chickens for the milk and eggs, I suppose you could have it on sourdough, so you've got a wild yeast, rather than a commercial one. That still leaves salt. I hope you used sea salt, mining salt is notoriously difficult and laborious. And if you used any condiments other than that salt on your sandwich, that's even more work.
I like mayo on my tomato sandwiches, how about you? That's more eggs, oil, vinegar, more salt, maybe some lemon juice, sugar... your little backyard garden is starting to turn into quite the plantation.
Or maybe you
bought the bread, mayo, tomatoes and salt? With $10, that leaves enough for a bag of chips, too. And that creates economic activity. Call it "I, Sandwich."
That box of lunch I have at the beginning of the experiment can be just bought with $10, the point is that it should have the same value as a $10 cash note, to be able to comapre
Anyway the difference is, if I just consume it, it will not create any further economy activity, if I spend the money to exchange for it, the money I spent will cause a chain of economy activities. So the economy activities are caused by currency but ends at consumption of the goods/services
Have you heard about the planned economy? In a planned economy, everything you get is just goods/services from the government, only very little money, so as my experiment shows, without money, there will not be a chain of economy activities. Normally people say the shortcoming of a planned economy is that they do not have some kind of price/market mechanism to efficiently allocate the resource, but I think maybe the core reason it did not work well comes from there is very little money used in that kind of economy