I can tell you the truth: Florence has more than 50% of its economy in Tourism. Not only incoming for restaurants, hotels, museums but also students that are coming here to study our language (Tuscany is the region where Italian language was born), our style, our culture, our design, our history.
We as a touristic sistem are very usual to give accommodation for students. Apartments can be rented at low prices, we also have the B&B formula but you will find it a little more expensive.
Here you have a few links that can help you find your best accommodation: