I've never had a 'real' outback GPS, hema, oziexplorer etc. I do have a cheap Garmin thing I bought 3 years ago and I'm amazed at what roads and tracks it has inside it.
On our last trip away we took some Westprint maps, they list waypoints and POI's on their maps (I suspect others do as well) with, (oh gee know I'm going to look like an idiot coz I don't know what I'm really talking about) latitude & longitude.
We used these figures with lat & long figures we got from our cheap GPS and could work out how to get from A to B out the back of nowhere.
We had trouble at one point, but we used common sense, worked out where the sun was and determined NSEW and got going from there.
To end my rant, yes $700 is alot for a GPS, I wonder if anyone buys those expensive ones anymore?