When deciding which Arles Pass to buy, be aware that the Museum Reattu has only the Nuages exhibit, no permanent collection or Picasso items. And they have the nerve to charge pass holders an additional two Euros to see it.  The Arles etc. Antiques Museum is excellent.

The more expensive Arles Pass includes both museums plus six other sites, but four Euros could be saved by buying the less expensive pass  --  four sites and one museum.