The most important thing we have, is our health.
Also by the way, if you only source groceries from chain supermarkets, then its no wonder food is costing you a fortune, reading into your duopoly comment.
Source from local markets for bulk of your meats, veggies, herbs from lower rent area's, doing a weeks worth of shopping in one go, in a lower rent area, you will save a small fortune over a given year. There is a correlation between item cost, and the commercial rent of an area where shops are located, from my experience.
It costs us a lot less to shop in Yuen Long for arguments sake, than it did in Sai Kung town, or at the gweilo aimed chain supermarket 10 minutes walk from our house. Depends how frugal you are I suppose...