It's a weird place Tailwag. You find these things mixed in with everything else. A few months ago I bought an electronic fluxgate compass in the North Sydney Aldi - its was between the carrots and the dog food. You sometimes have to ask and they get the things from 'out the back'. They publish their forthcoming 'special buys' here:
http://www.aldi.com.au/product_03/index.html
Worth looking every week or so.