Checkers, a household-name grocery store, has a decent wine aisle with a selection of the more common brand names available, although they won't carry any of the high-end or boutique wines.  Prices typically range from $4-20, and for $20 you can get some great bargains.  They also carry "Oddbins", a marketing gimmick in which the retailer conceals the winery name and only tells the grape variety -- it's a grab bag approach which forces you to pay attention to what you're drinking, and not the label -- good idea! 

Find them here with postal code 0001.