I would need both hands fully functional at all times during this weekly adventure, as it would, at times, involve going to various supermarkets with very different atmosphere. The more civilised ones like Wholefood is like a walk in the park compared to the more Chinese orientated super market such as Ranch 99, where, the mentality and aggressiveness of middle aged women reaching over "on sale" produce is comparable to (if not worse than) hungry 3rd world country kids fighting over food. (those kids probably have better manners) THIS is when you'd need both hands to, a) have full control over the shopping trolley- as there are no rules there! and b)guarding and defending yourself from the sudden arms reach of fellow shoppers..
The Chanel wallet on chain comes very handy here, and it fits all the necessary stuff. Flats are also a must, and a comfortable zip up that would allow full arm movements as well as to keep warm!! Supermarkets are always SO cold that I often wonder if they get electricity for free! and finally hair up ready for the battle!