A supermarket open 365 days a year is surely handy....but!
Unfortunately, you may find some... mineral water offered with a 50% discount that is... still as expensive as beer...
Avoid (if possible) the supermarket at ground floor.
Fun Alternatives: If you're leaving Milan, buy your drinks, food, etc in a "normal" supermarket: Esselunga, Unes, Pam, Lidl, etc
This is a special WARNING for all male visitors of Milan!
There are two streets in Milan which you have to AVOID: first one MONTENAPOLEONE, and the second one Via della SPIGA!
This two streets are probably the most expensive streets on earth. There are no prices at all in the shop-windows. DO YOU KNOW WHAT THUS IT MEAN!!!
Remember it well!
Once again. If you're rich and have money to throw away, Via Montenappoleone is the place for you! Louis Vitton, Gucci, Armani, Iceberg, its all there! I'd heard so much about the shopping and couldnt afford to shop there!
Milan is an expensive city!
And specially the down-town area.
When I lived in Milan I lived in the old part of town by the canal, called Navigli.
Navigli is my favourte part of the town and the food is much more cheap here!
There is a lot of picpockers here and people begging for money - so be aware!
If you want to have a great capuccino at St. Ambroeus or anywhere in Milano, you can have it at 'the counter'. Doing this they can probably charge you no more than L.1000 over the normal price; which is always much more reasonable than paying three or four times its real price if you are seating at one of the tables.
Same thing happens in most of the beautiful cities arround Milano.