Turin is in general an affordable place with lots of centrally located B&B options in the 40-60 € / night range. There is also a large choice of hotels. Classy options are Hotel Victoria, the Hotel dei Pittori and the two NH hotels at Piazza Carlina and San Stefano. Townhouse 70 is a popular mid-range place. In case you make a telephonic booking at one of the NH, it is worth the effort to ask for a university discount (no guarantees, though).
Participants who are interested in student accommodation (ca. 30-40 € per night) should get in touch with the organizers via the contact form since the booking has to proceed via the university. The private market is, however, not much more expensive and the booking process is much easier. There are also lots of AirBnB places but we hesitate to recommend them due to their impact on the housing market and the outrageous fees they charge.
Especially for small B&B’s, it is recommended to book directly at the accommodation: they often give you the “real” price without the 15% commission that booking.com and similar sites charge them.