Dear X

What do you do when you know a fellow ebayer is being dishonest in their auction descriptions? For instance, one ebayer I know lists things as "NWOT" when I know it has been used. How do I know?, she has posted pictures of her daughter wearing the clothing in groups. Further, she charges high shipping of $10, for something that costs her less than $5 to ship. Some of her buyers must know this now, seeing one posted as such in feedback, but as a fellow ebayer, what do I do? As a designer, I would not want my work being thought of poorly, and being misleadingly labeled as "new", and as a buyer, I do not want to spend my hard-earned funds on something I thought was new, but has wash-wear, etc.