I used to barter my labor of doing chores around the house for the extra slice of pizza my brother didn’t eat. We also used to swap snacks at school, everyone had a different rate for gushers via dun ka roos
I remember as a kid I would exchange Pokemon cards for homework answers and also because my mom packed my lunch I could trade her homemade treats as well.
In grade school I traded baseball cards with my friends. My team was the California Angels. I would trade my Sandy Koufax of the Dodgers in order to obtain a Jim Fregosi of the Angels. Even though Sandy Koufax was more accomplished, I was happy with the trade because I was a bigger fan of Jim Fregosi. If I had been more shrewd, I probably could have gotten a Bobby Knoop card as well.
I remeber exchanging sweets for other sweets with my brother as a child. That was a fair transaction.
Then I remeber I exchanged some stickers for something else, could be that were sweets as well, I don’t remember exactly. But I remember that I regreted later making the transaction as I thought the exchanged item wasn’t worth as much as my sticker as it had a metal - rainbow shining basis with one of my favourite cartoon characters on it.
The first barter I´ve ever used was when I was 5 y/o. I use to trade good behavior for things. For example, If I wanted a new Toy I needed to get a School diploma. I think for the age I had at that time it was a good bargain. But as I grew, the cards became a thin, if you wanted a specific card, you needed to give something in return. It could be money, or simply another card. And yes all the trades I conducted where fare for all the parties involved.
when I was in middle school, I used to help people out with their homework in exchange for food- something for lunch, or snacks. Looking back, it still was a great trade because i got to save all my lunch money i got from my parents 
My friend and I exchanged shirts. I had a multi-coloured blue shirt that was too small for me and my friend had a solid blue one that was too large for her. It worked out perfectly because we each gained something better suited for each of us, while not losing out on what was important which was something to wear.
I once exchanges a watch for another watch. For me it wasn’t fair and for the other boy i guess it was a great deal. I was younger
Than the other boy and in the end made the deal he asked for…
I usually barter my service for money or toy. I also barter my used books that I’ve read for other books that I have not read yet.
I think it is a fair exchange, otherwise, I would not agree to it. You give value to what you need, even if others think it is unfair, for me it is a great exchange.
I once traded a ps1 game for 3 waldo books in primary school. I really wanted those books so and I played the game multiple times, but looking back I could have asked for a couple of toys as well.
I remember back in '80s when I was kid that we did barter also for marbles, football cup stickers for our albums, and my favourite barter of all was for comic books. With some romantic sentiment I look upon those days of youth, when every time I felt that I’ve got good end of barter. Pretty much it was a Win-Win for both sides. I can’t say the same about these days when I have to give 55 hr of my week to my employers and in return I receive wage which allows me to meet ends in my life. I want more comic books & Crypto in my life, and more time for everyone and everything 
Many of my earliest bartering exchanges have taken place in Minecraft. On different worlds with my friends we would often specialize in different services, for example on one world that was wood. My friends would come to my wood shop and exchange a set amount of diamonds or iron and all parties would be successful.
my first Barter transaction was to exchange marbles. 1 big one for two little ones
I remember trading garbage pail kids.
About trading labor for clothes. As a child I worked for people for a whole year to get some clothes. It was very unfortunately, at the end I didn’t get any clothes. At times, other people would barter with potatoes, beans, corn or meat for labor work. No, it was not fair. The other person did not keep their word.
Mmm…a barter transaction. When riding motor bikes as a kid I used to need fuel for the bike. My father got sick of me just coming and asking for fuel all the time so he made do jobs for a full tank of petrol. Very often it was 1hr of clearing on our bush property for a tank of petrol. This was my first introduction to barter.
The only bartering that comes to mind from childhood would involve sports trading cards. My neighbor down the street was a few years older than me and would convince me that his cards were of equal value to the ones I owned and he wanted to trade for. I would later discover the cards he offered me were less rare than the ones I gave up.
This would harken back to gold/silver not being easily able to verify (weight/melting down) for actual value. I had no way of knowing based on looks alone that his cards were less valuable than mine.
I was trading hockey card in the school yard when i was young here in canada we would trade it against some other cards of others players of course. Some had more value because of the scarcity !
Every time I come over to my cousin’s house, we trade Lego. I also used to give my brothers and sisters candy, (cause I had a lot of it and kids are kids,) if they do what I ask. And also hot wheel cars. Of, and I also remember writing an IOU on a paper cause I was supposed to trade a some candy for a cool hot wheel car he had.
I was in a rock band years ago. And we wanted to record some songs we had written. The beginning of the recording project started off really
well. We had a savings fund for the band(money made playing
shows or selling merchandise). But that money ran out fast. The owner of the studio
said if we would come in and clean the studio inside and outside periodically, instead of
paying us, he would give us free studio time. That was a great deal, cleaning a recording
studio for time to record our music.