During my time in Montpellier, about 3months I never once payed to ride the bus. Everyday I would take it to and from the beach. All you need to do is get to the bus depot, get on with confidence, there is a ticket validating machine in the middle of the bus, the driver cannot see what is going on because the buses are fairly busy, so just walk right on by and ride it to the beach and do the same for coming home, if a problem does arise, play dumb that you didn't know where you get the ticket or what, they sell the tickets out of machines, so it's easy to bluff!