As I said in another post, we stayed in a ryokan hotel in Naha. Located in the center of the capital, Andon is a very short walk from Kokusai-Dori, the main shopping street. More precisely, the entrance is on a less touristy street, near the Mitsukoshi and OPA department stores. Within a few seconds walk from the hotel, you can access shopping malls, restaurants, bus stops... And it's located right between two monorail stations.
We were charged 2,500 ¥en per night per person (approx $30). No matter if you're a couple or alone, everyone pays his/her share and the size of the room provided subject to availability. In Okinawa, the tourists have plenty of choice to prefer one of the many big resort hotels with spa and swimming pools. But these are not in the same price range and, generally, these complexes are located on the coast rather far from the city. Given the price gap and easy access to the beaches from the city, we chose a more informal hotel : the ryokan type.
Okinawa Yado Andon is very clean, has regular sized japanese rooms and a welcoming staff. Everything is Japanese style: you sleep on futons prepared on tatami rooms and walk with slippers inside the hotel. There is a small TV in each room, air conditioning (with charge, though) and shared bathroom. Customers are polite and kind of quiet, we didn't hear any noise during the stay.
In short, if you travel to Okinawa and Naha in particular, with a limited budget but without compromising on Japanese service, do not hesitate.