I'm not going to be back in Oz for a while and I don't have any sort of international payment option, but Mandarake Shinsaibashi has two of the sets going for 2100 Yen each at the moment. That's a little over $25 AU.
If you can find someone who's coming to Osaka for a holiday and they're willing to help that'd be your best bet.

They've been there for a while, so if I can get freaking Paypal to recognise my Japanese address instead of just refusing to work altogether I'll let you know.