I was reminded of this story I read long ago by this question:
Unfortunately, it is just possible that this particular story was a french original. Probably not, but just possibly. Anyone familiar with french SF, just in case ?
Anyway, in this story, there was a twist. Everyone wore the same clothes, ate the same food, lived in apartments perfectly identical. But the rich people bought the very same items much more than the poor ones, and the only difference between the items were the price tags that were visibly displayed. So the rich could boast about paying exactly the same objects twice, ten times or one thousand times more than the poor ones.
Of course it was just a parody of a dystopia, but I forgot the other details.
A warning. What follows might well be a false memory, but it is just possible that this is a story within a story. Within an "outside" story taking place in our own world, or a world very close to ours, a writer writes the above story, or tells a friend a synopsis of a story he is writing, or wants to write. For some reason, I vaguely remember that the idea for this story came to the writer from a reflection about decaffeinated coffee. But this is very fuzzy. The story I am asking for might be the only story after all, not one into another one.