The only thing I can remember trading purely on a barter value (not having to buy it myself in exchange for someone picking me something up on their way over to my place) would have been our lunches in the school yard.
Having some European background, the lunches I would get would usually garner quite a bit in return and I’d often halve what I had and got back twice as much in volume. I would usually choose one savoury from someone for one half and a couple of sweet/snacks for the other half.
I used to barter toy figurines between friends. I would also trade Hockey cards and even food items.
The only thing I can think of is food. Switching one food item for another. For example, I’m eating pizza with the family and we trade slices, so we could try different ones. In those instances, the trades were fairly fair.
As a kid I used to trade pokemon cards based on rarities/cards I didn’t have. I remember trading a shiny Charzard for a common card that I didn’t have. No where close to fair in value, I gave up a rare card for something everyone had. (Accept me apparently)
As a child, I would barter my Pop Tarts for Frosted Flakes cereal. It was a fair exchange between my cousin and I since we would both have a new variety of food.
I recently traded a older boat I had fixed up into good working order for a newer more valuable boat but still required work.
I feel it was a fair exchange as I traded a older boat that I had put a good amount of work into for a newer more valuable model that required work but I was willing to do the work to make some profit after I was done with it and the man I traded with wasn’t so he was also happy because he now had a tidy boat he could use without having to do any work.
I have traded a rare pokemon card for a fake pokemon card I made myself, printing paper and sticking it together when I was about 8 years old. It absolutely was not a fair exchange since it was some kind of fraud, but I am proud of it, I made my money, and it definitely was fair for me!
I remember exchanging yugioh cards with my cousins. I think it was a fair trade , like Drake would say 
For me, it was cards and games.
Somehow presents are a way of bartering!
When I was 18 I swapped a Suzuki B120 motorcycle 
to my buddy who had no cash and needed transport, he had a snap on socket set and a blank firing 9mm pistol 1911 cant remember the make, I think we were both happy with the deal, I had totally forgotten until today:-) If I ever see. him again I shall ask him!
I have often exchanged lemons for eggs with a friend of mine, we both have an abundance, so there’s no argument about amounts or the exact amount of each item in the exchange.
As a kid I once traded my NES game Megaman 2 for my friend’s NES game Double Dragon.
Looking back, I think it was a fair exchange because both games were unplayed by the recipient at the time, both were on the same console “standard”, and both were popular titles that we were reasonably confident that we could trade again with others once we were done playing.
I often trade lemons with my mother-in-law in exchange for lemon meringue pie. Definitely not a fair trade 
When I was 8 years old I have a pair of skates that was I no longer wanted. My friend Chris wanted them, but he had no money to buy them, He had a football and baseball bat he offered for my skates. i agreed to make the exchanged, and we both got what we wanted.
I used to rake leaves as a child and my parents would take me to the movies, it was a pretty fair trade.
A barter exchange that I’ve been a part of that I can remember is going back to my childhood with Pokemon Cards. I would typically exchange 2 or 3 holographic cards for another holographic card that I sought interest in. Looking back, it most likely wasn’t a fair trade. I most likely traded more valuable cards than the one I was looking to get at that moment.
My first barter was with my classmate. She gaves me an apple for a banana - so I think it was a good deal because everbody was satisified and this is the main thing - that both of the “game” are happy. But when you get older youll recognize that the real world isnt a fairytale 
From quite early on I was interested in trading card games. At that time I was recieved parts of an animal encyclopedia which came with free cards with the creatures on. I wasn’t interested in those but decided to still put them in my binder because where else do you keep cards?
In the end I was able to trade most of those animal cards for some decently priced cards from mtg and ygo. I definately got the better end of those trades.
When I was a kid, Pogs were a popular game. We used to trade pogs with each other, and sometimes it felt fair, other times not.
Several years ago I sold a car in exchange for a television as partial payment. Not only was the television a desirable object, it was something that I needed and saw it as useful.
An understanding was reached between me and the buyer making the offer of the television regarding the portion of the price represented by the TV for the car being purchased.
Both parties, buyer and seller, were pleased—making the transaction a fair exchange.