nothing casts a bad impression on a buyer than seeing a out of line shipping cost. if your shipping costs are about the same as the cost of an item you are going to loose bidders. shipping costs should be very close to the actual cost of shipping as possible. if you charge for packing or have the package packed by a shipping company you will loose customers. learn to pack and pack it yourself. learn what shipping costs will be and use these figures. if you ship overseas and are not sure of the costs , tell the customer you will refund any shipping payment not used, its easy to do using pay pal. you will make a happy customer and possibly a new friend.