One of the most contentious issues when selling used books is how to honestly describe the condition of that book.
The main problem being that condition is subjective.
What you may judge to be ‘very good’, the buyer may think it’s merely ‘good’ and will complain if the condition description does not meet their expectations.
Although, I have to admit, I am often annoyed at buyers who purchase a book described as ‘good’, and complain it is not in ‘new’ enough condition to give as a gift!
Items marked as ‘good’ can have a plethora of ‘faults’ and still come within Amazon’s guidelines for that condition description.
For example, used books in good condition might have previous owners’ names or slight cover rips, or inner markings such as underlining.
The issue is that most buyers do not have a clue what something described as ‘good’ is, and so can have unrealistic expectations on how a book should look.