Wonderful little device made by Televue which attaches to some of their eyepieces (eg Ethos, 2' Panoptics, 31T5 Nagler etc) and allows you to get perfect and comfortable eye position.
http://www.bhphotovideo.com/c/produc..._Extender.html
Inclusive of exchange rate transaction fees these will cost approx AUD$60.
Comes with original box and packaging.
Asking $45 inclusive of shipping anywhere in Australia