I have been sewing since I was a child and I love to buy fabric. I discovered Gori Tessuti in Sesto Fiorentino (just outside Florence) a few years ago and I go there every time I go to Italy. This place is huge!!! It is a wholesale warehouse that seems to sell ends of lines. Sometimes I find lots of great stuff and other times not, but it is always worth a visit. www.goritessuti.com
There are no elegant displays. You need to gather all your strength and forage.
There are all types of fabrics available if you are prepared to search.
It is a wholesale store, so you will need to provide a business address to buy from them. I have bought small amounts of fabric in the past without this, but lately I have heard that they have been more strict with this requirement.
It can be a bit tricky if you want something from the bottom of the pile, but there are several gentlemen there to help. It helps if you have a bit of Italian as not many of them speak English. On the most recent trip they were expanding and perhaps straightening up a bit. Who knows what I will find next time.