We're looking to take the train from Venice to Padua, and I've read here on some posts that the fare is only about 3 euros one way. I went to the trenitalia website though and only see it as low as 9 euros per person for the Mini fare but I believe that's not for the regionale trains. If I wanted to go with the regionale train and thus the lower fare, is that then only available the day of at the train station? Is there a limited number of tickets available at this price? Do train tickets fluctuate in price (like airline tix) based on availability? I was looking to pre-purchase the tickets before we leave as I thought that may be easier. We would be travelling next month.