Microsoft Bluetooth Notebook Mouse 5000 - OEM $61.60 @ Techbuy. shipping $9.90 Au wide
Now I found one dropshipper with it for $45+del but I'm not too keen on using dropshippers.
BUT if you can find 2 other friends who need one, a few retailers are selling 3 packs of these for quite a saving.
Ozdirect have them listed for $121 + Del
ITparadise have them for $125 + del