My
I had a customer buy 1 raw comic for about $20 a month or two ago.
There was a defect the buyer didn't like and he wanted to return it, he was going to pay return shipping.
After thinking about it, I told him to keep the book as a part of his collection until he found the copy he was looking for and that I would refund him 100%
The result: He thanked me and left me great feedback and said he would be back.
Lesson: I lost a little money short term, but I did the right thing and took care of my customer.
Lesson to the seller in this case: IT'S YOUR TURN