The price that can’t be beat is at Harbour View Hotel (tel. 504/425-3772, tatianaluna22 [at] yahoo [dot] com), where rooms rent for the bargain basement price of US$2 per person. While the bathrooms are shared, and the water is cold, the place is clean enough, and conveniently shares the pier with a couple of the most popular establishments in town, Tranquila Bar  and Indian Wok restaurant . Harbour View is affiliated with Parrots Dive Center  and gives priority to divers and nondiving friends who are accompanying them.
Another good deal is Loma Vista (tel. 504/425-3243, US$7 pp), with clean, sunny rooms with communal kitchen facilities (sink and burners, but no fridge) and a porch with a picnic table and hammock.
The simple rooms at Monkey Tail Inn (tel. 504/425-3155, US$5.25 pp) are in need of a paint job, but there’s a small porch and wireless Internet throughout the hotel, and it’s also home to Cyber Monkey Internet café. It’s acceptably clean, although flip-flops are recommended for the concrete cold-water showers.