In visiting Rome, we have often been able to find medium-sized supermarkets where we could buy mineral water, wine, yogurt, cheese, etc. at very reasonable prices. One that we frequent is located in the basement of a department store. But in several trips to Florence, I can never recall seeing a supermarket in the main part of town. There's is always the mercato centrale and other smaller ones, but does anyone know where there might be a supermarket in downtown Florence?