Getting to Calasetta is relatively easy with the (being enhanced) Cagliari (soon to be) International Airport. It's a small and relatively efficient little airport. Flights generally connect through Milano, Rome, Naples, Genova, Verona and a few others. In the summer increased service is from the rest of continental Europe. It's approximately 1 hour from Cagliari Elmas Airport to Calsetta.
Get a moped. All you need to do really is to get from the beach to home and from one dinner to the next. Of course you'll want a car to cruise around to other areas, but really you could get by with a swank little vespa.
If you find yourself here. You are about 5000 miles off course. This Sardinia is in South Carolina and the picture makes a great postcard that I sent to my friends in Sardinia (italy).
Sardinian roads are not as wide and spacious as the roads in America, but a major rehab of the Carlo Felice from Cagliari to Sassari had made crossing the island a relative breeze.