Similar deal was posted here: http://www.ozbargain.com.au/node/4816 but this is $3 cheaper :)

Not sure if this is just for the Wynyard store, but the RRP is $19.95 and seems like a good deal.

Officeworks catalogue sale. Page 24. Valid between 29/05/2008 - 08/06/2008

(EDITED: Added product codes)

VARTA 48 Pack: VAHEAA48C

Also has;