I was once waiting at the lift at costco with a guy who had a trolley full of bags of flour. Turns out he owns a restaurant, and it's cheaper for him to get flour from Costco rather than his suppliers.
Talk about coupons brings me back to the days when I used to sort them all out for my Mum as well as the green shield stamps!! showing my age now!! will be glad when Costco and Aldi come to WA.