Take any Coles receipt to Liquorland (which will almost certainly be right next door) to pick up a 6er of Monteith's pale ale for just $10, normally $21 (or $19.46 at Dan's).
Using the same docket you can also get yourself a 6er of any Matilda Bay "Yak" variety for $12.
$22 for half a case of pretty decent beer. Rinse and repeat with another docket (maybe buy a single bottle opener?) and the carton is $44.
Dinner sorted.
Just bought something at coles and nothing on receipt?