You can also reflect this in the star system when giving feedback. I have heard that system changes are going to see sellers screwed over if they're not averaging 3.5 stars, so obviously make sure you give him one star for everything - especially the postage one!

It is quite common to jack up the postage, especially on international items. It lowers the fee that sellers pay to ebay, beause it's a percentage of what's bid. In second hand bicycle part circles it is completely accepted that that's just what you do.