Dazz78 replied:

Stayed at Greenbank last september. The cost per vehicle was $150.00 but this included a bit extra because we wanted access to another creek on the property and needed to be shown the way. As far as I am aware there are no amenities at the main camping area and the nearest fresh water apart from billabongs is back at the Werean River where it crosses the Savanna Way. I did see a couple of water tanks but even if they did hold water I do not think they would be for campers use. Access to the river I am unsure about, most of the Robinson River that I saw had sheer cliff face but this flattens out toward the mouth where there are a few creeks. There would be reasonable access for a small boat somewhere. As I mentioned we camped in a differerent area and did not see much of the main camping ground but I hoped this helps.

Regards
Dazz.