Well, when I was a child I used to exchange bijou (I made it by myself) for school supplies as pencil, stickers, etc. There were itens more available than others, so I think it was a fair exchange.
The other trade I made, It was when I taught as a Chemistry/Math teacher, but I disagree with the payment per hour (since I had to work at home doing/correcting exercises and preparing classes and It wasn’t contabilized).