Yeah it is quite common for the postage to be high, but genrally indcates bad ebayers having brought and sold stuff for years.
I had some american dealer try to tell me that to post out a carby was going to be 40dollars I told him to get f$$$ed. As I have brought heaps of parts from the us and postage for a swingarm plastic tank sprockets only cost me $40US. After heaps of messages he wanted basicly for me to pay for his time on hourly rate to wrap the item, also to chuck some juice in his tank so he can get to the post office, then pay for postage. mmmmm Never buy off these people and they will learn.
I only charge what the post office charge me same at my place of work, suppliers try to charge people 25bucks for 8dollar courier and these are big companies, so you really got to whatch freight as it can kill a good deal. If it is not shown ask before bidding and save yourself a whole lot of stuffing around.