My husband & 10-year-old son & I stayed at the Hotel Constantin for 2 nights in late June. There is nothing at all deluxe about this place. The rooms are small, the shower stalls miniscule, the breakfast adequate but not that special (croissants with jam, coffee, hot chocolate), the location convenient but not fantastic, etc. But the price was right, and we found the service super friendly and attentive, which is why it's getting 4 stars.
Our first night there was tough: The room was cramped & musty, we were plagued by a mosquito, & I was kept awake all night by a crying baby and neighboring toilets. The next morning we asked if it was possible to move to another room (the other option being to find a different hotel), and the proprietors moved us upstairs to a much nicer room. They even moved all of our luggage for us while we were out sightseeing. If you're reserving a triple, avoid Room #5. Room #7 on the third floor is not much bigger, but quieter & more cheerfully decorated.
They were also really great about recommending restaurants & local activities. A restaurant we loved: L'Ecrin, just northeast of the amphitheater. Wonderful tapas, great service, pizzas perfect for picky kids. Another recommendation: the Musée départemental Arles antique, easy walking distance from the hotel. Scale models of the theater & amphitheater during Roman times, cool sarcophagi, mosaic restoration projects, insights into ancient life in Arles.
If I were in Arles for more than a few days, I'd probably want to stay somewhere a bit roomier & more comfortable. But for a short stay on a budget, this place was fine. And the warmth & helpfulness of the proprietors made all the difference in the world.
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC