We are staying in Ravello in June and would like to take a day trip to Paestum. What are the options and approximate costs?
First you have to get from Ravello to Amalfi, the bus is the usual choice.
From Amalfi to Salerno you could take the bus or the ferry. The ferry is significantly faster (35 minutes vs. 75 by bus) and more comfortable but costs a little more (€8 vs. €2,40).
From Salerno to Paestum you can go by bus or train.