To be fair, I've sold hundreds of things and have bought a few things too and most of the time I've had no problems.
I've now had someone raise a dispute. She bought some children's clothes for precisely £1.63. Cost a lot more than that new. The clothes in particular were used no more than 3 times. I can say this for a fact because my husband bought these particular clothes for a holiday and they were too small so hardly got any use.
I offered a refund but of course she doesn't want to send them back because sure of the postage.