I think John got a point about going to the post office and waiting in queues, im a active ebay seller ,that sells at least 200 products in a week, and my customer service is right up they with Johns(not boasting or anything) but i have my items packed within 20 mins of a order being placed if im home and if im not then it is packed straight away when i get back.
I used to have to go to the post office every day to get 10 or so products posted and its a hassle as you have to wait 20-30 mins before being served and then another 30-40 mins getting the stamps paper work etc done on the packages.
So i just get them printed online now whoch works out cheaper, and have someone pick them up,
So when you do work out you p+p charges bear in mind how long it takes to pack, the packaging cost, and do it online as most of it works out cheaper and is hassle free.
I CALL FOR INTERNATIONAL FLAT RATE