Hi, It really depends on where in Sardinia. By air or Ferry and if you're in Rome by fast ferry from Civitavecchia port of Rome.
Hope this helps
Ciao from Rome
http://www.rometourforfamilies.com almost 8 years ago
I got a super cheap flight from Genova to Sardinia for $20 or something crazy like that on RyanAir. If you are traveling light, you can get away with the discount airline without paying too many fees. They have direct flights from all over italy to Sardinia. about 7 years ago