Andrews Communications Systems has them for both 1.25" and 2" eyepieces for $2 and $4 respectively. They're under the 'Andrews accessories' section in the list linked below:
http://www.andrewscom.com.au/site-section-10.htm
Aquila Optical & Electronics (AOE) has the 1.25" for $2.99, as per attachment (scroll down to bottom of linked page):
http://www.aoe.com.au/eyepieces.html