I try to use the local shops as much as possible. Especially bakers and butchers. Quality is way way better than supermarkets. Cheaper to.
The greatest trick the supermarkets have pulled is that they are cheaper than the alternatives.
Disagree about the Co-op having poor quality food. Their chickens particularly the free range ones are far better than any of the big supermarket ones.
I wish I could buy everything from the local small traders but hours of work do not allow it, also, tend to visit Waitrose on a Sunday afternoon or Monday evening and pick up the bargains from the meat and fish counters!