It is annoying when the P+P is more than the item you are buying, so I avoid those people like the plague. I don't use ebay but there are companies that charge a lot for P+P. I think they use it to help cover their admin costs and that helps keep the prices of the items down. They have to make money somewhere.
I think charging a lot for P+P and not even bothering to use suitable packaging is to say the least cheeky.
Jan