When I was growing up in the 1950's and early 1960's, several of my friends and I developed a really fun hobby that we called "The Trading Post." We got the idea from watching Westerns that portrayed how much early commerce consisted of trading, rather than the use of gold or money. Also, my brother was a collector of baseball cards, and there is a great tradition of trading of baseball cards among young collectors.
We used candy boxes, especially the two layer ones that opened so that the upper and lower levels could be viewed, and then filled them with cool stuff that we enjoyed collecting. For example, being girls, we had pretty buttons, jewelry, charms, the toys you get from gum ball machines, special art supplies that were hard to get (like a small tube of glitter or rubber stamps), ribbons, cool bottle caps, marbles, tokens from board games, such as dice, small toys or tiny plastic animal figures, rocks and crystals and so forth. We would then "open the trading post" during recess at school, or when we played after school, and traded for items we liked from each other's collections. Parents got involved because we'd try to think of cool things to add to our collections. For example, one of us wanted to get sawdust from her dad's wood working shop and color it in batches of different colors (think of it as a poor girl's sand art supply). Since we were all working class poor it was also a way that someone could get a hold of something special, such as a scrap piece of pink satin or pretty lace.
It was amazing fun and since it didn't involve money, just good hearted bargaining, it is a great activity for kids to learn how to barter and how to acquire without it being all about money. I still have stored away in my belongings items that I used to have in my trading post. For example, there used to be a handheld game that had sliding numbered tiles. My friend had a few of them and I traded to get the one that had my birthday number on it; I still have that one!
It's also a way that kids learn that even if they lose interest in certain toys that they have that they can trade with another kid who might really want that toy. Being more of the arts and crafts kind of kids we stuck with small decorative items for the most part, things that could fit in the large size candy box (like a Whitman's). I think the largest things we traded were what we called Nick dolls, which were popular then (they are the long haired troll dolls, ha).
Anyway, I thought I'd share this personal recollection with you because it was an enormously fun and positive thing for us young kids to do and you parents might want to try it as yet another alternative to TV, video games, charge card mentality etc. It also tends to promote a hobby and collecting spirit in kids at a young age. Best of luck and enjoy!