Very nice place, well preserved mosaics, but do not let that fool you. When we bought our tickets on Nov 19, I noticed right away that the tickets were stamped for Nov 09 and also tok account that the ticket numbers were not consecutive. I showed that to the attendant and he tried to tell me that "it is the same, it does not matter". I speak fluent italian so I told him that I wanted new tickets with today's day and consecutive numbers. He said someting in sicilian to the lady that was there with him and with a very angry face gave me the new tickets.
I could have let him steal from his employer, or the government, it made not difference to what I paid but had I been italian that guy would have seen his last day on the job.
It happens that the tickets were also good for visiting two other places in the area where I would have had to dish out another 15 euros, but then, italian or not, that guy would have been fired.
This was the only incident of this type during a two week visit to Sicily and Rome as it has been in prior visits to Italy. Speaking the language makes everything easier and better.