Lol, just be careful.
A 2000 Euro cash payment to a service supplier is illegal in Italy.
Looks like they have asked you to pay "in nero" i.e. not an official transaction so that it will not show up in the hotel/b&b accounts and they will not have to pay taxes on it.
If it is for a dozen different rooms for different people in the group in could be legal. Depends on what kind of receipt is given if given at all (which by law you should get...lol).