Why get upset with high shipping charges, as long as they are clearly stated in the listing? I never bid on an item without working out what the total cost including shipping will be, and set my maximum bid based on that. If the charges are not stated clearly I either do not bid, or if it is something I really want, I email the seller and get a number - no number no bid, it's easy. There are many listings which provide no information at all on shipping, this screams AMATEUR to me and I usually ignore them unless, again, it is something I really want.
You have a legitimate complaint if the item is not properly packed and that would be a reason for at worst a neutral feedback with a comment about the poor packing. If a seller keeps getting this sort of feedback they will soon be out of business. In my own listings I make it very clear what the buyer is required to pay, including how to work it out for multiple wins. I do this to speed up the transaction and save myself answering lots of e-mails on shipping costs. It is amazing though how many buyers do not read the listing completely and still email me asking for totals.