I've found quite a few independent shops in the wider area selling quite a few of my usual grocery items much more cheaply - the international supermarkets on Catford Broadway in particular are great. Branded things like Lavazza Rosso coffee, Oatly oat milk, Lurpak butter, Heinz tinned goods - all up to 20% cheaper than Sainsbury's. Plus the bonus while you're there of a huge range of good value dried spices, decent quality fruit and vegetables, meze dishes etc. I acknowledge it doesn't have the convenience of just doing The Big Shop at Sains once a week if you're time poor - though I really enjoy getting on my bicycle or going out for a wander of an early morning, seeing the sights of places I don't go often, and doing my errands at the same time.