Many of the "oldtimers" on this board started out staying in similar cottages with outside cold water showers and outside flush toilets - and loved every minute of the stay. If the property doesn't have fans available for the room, they can be purchased either in downtown Negril or Sav.
Another budget property with similar old style units is Secrets Cabins which is right on the beach (part of the Firefly property). Check it out.
http://negril.com/hotels/secrets.htm