Trade me is a good site but there is a lot of xenophobia with foreign traders including Australians.
New Zealand has some really arcane rules too.
Australians are allowed on Trade me, but must state costs in NZ$ and buyers have to be authenticated (Trade me sends a letter with a code to your address and you must enter the code.
Also coins are not allowed to be sent in the mail in New Zealand, so you must disguise them, making it hard for us to send.
NZ also charges GST and customs duty on anything foreign over $60 NZD due to protectionist rules.
In general I find NZ coins cheaper in Australia and Australian coins cheaper here, same with stamsp - you pick up Australian stuff for a song, but Kiwi stuff is priced out of contention.
Trade me is good overall, very few scammers a ban on Chinese and anyone not from NZ (99%) and a few Australian, British and USA accounts - mostly locals who ship hard to get music, DVDs and books from these markets (I buy a lot of my Prince stuff there).
Their payment system is Ping, which is instant credit and debit card, it costs no fees to use, but sellers are hammered witha 1.95% fee on their sales.
Trade me also charge a 7.9% success fee on anything that sells.