I spent an extended weekend in Sorrento in 2015 (from April 23-April 28) organized on Glocals by John K.
We stayed at the Ulisse Deluxe Hostel in Sorrento which was inexpensive, nice and centrally located.We only used public transportation including the airport bus from Naples to Sorrento. The boat to reach Capri on our first full day in Italy, by bus to reach Amalfi and Ravello on our 2nd day (we went on a hike walking down to the coast from Ravello), by boat again to reach Naples on our 4th day (we had reserved a walking tour in Naples organized by two students). To reach Pompei and the Vesuvius we also used public transporation though we reserved a private guide with whom we toured Pompei and also the Vesuvius. We did take the train to Pompei.
I have copied an email received from the tour office we used to reserve our guide for Pompei and Vesuvio-their email address is: [email protected]
On the 25th of April at 8.30 am the guide will came to pick you up at the Ulisse and you will walk together to the train station of Sorrento (800 meters by walk from the Ulisse). You will catch the first train to Pompei and once you will be there you will have a full tour of the ruins of 2/3 hours. Then, you will catch the Bus (from POMPEI ANFITEATRO SQUARE nearby the ruins) to MONT VESUVIUS and you will spend there approximately 2 hours. The price for the trains and the FULL DAY (7 HOURS approx.) with a private GUIDE (English speaking) will be euro 250.00 for 4 people.
IT is not included in the price the ENTRANCE to POMPEI - VESUVIUS and the bus from Pompei to Vesuvio and back, It will be euro 31 Per person.