When I went to Sardinia on holiday I stayed at the Aloe Bed and Breakfast. It is an apartment located in via Don Minzoni, (with three exterior bedrooms, kitchen and two bathrooms), run by a middle-aged couple. It isn't right in the center, but it isn't too far away either. if you have a rental car I recommend it one hundred percent. It is very clean, cheap, and breakfast is very good. The owners live right across the street and they treat the guests wonderfully. Do not hesitate to ask them to recommend places to visit in Sardinia, with maps and routes which they may point out. You rent the room, and with that, are entitled to the two bathrooms and the dining room. If you have something to leave in the fridge you can too. In addition, free parking is just opposite the apartment. Extra beds are available. The price of a double room can vary from 44-50 euros, depending on the time of year. You can book online.