If you have a couple of weeks to spare and want a great 'free' camp then contact Menindee tourism and volunteer to run the info centre . I recently ran it there for 3 weeks and loved it. Water, power, all amenities in exchange for 4-5 hours a day!  The centre is run only by volunteers, and when nomads are not available, a couple of local ladies keep it open. Tidy safe town that takes pride in itself!