There is an Auberge de Jeunesse youth hostel at 20, avenue Foch. It's within walking distance of the train station. Another favored alternative is sleeping in the streets. Place de la libération offers a hospitable sidewalk with a boulder dedicated to two American WWII pilots shot down over Arles under shelter of which you may sleep.
There are a few hotels apparently built within parts of former abbeys, such as Hôtel du Cloître by Saint Trophime. Also, there are tons of hôtels de tourisme.
Other hotels:
Résidence Club Le Domaine de l'Estajan
(http://www.pv-holidays.co...) Résidence Club Le Domaine de l'Estajan +33 1 58 21 55 84, The residence is made up of several small buildings, no higher than one floor, spread around the Maeva Camargue estate: Les Roselières, Les Oliviers, Les Amandiers, Les Piboules, etc. A large number of leisure activities riding, tennis, golf, etc. and relaxation facilities balneotherapy centre are available on the site.