Yeah.
What's it look like? Good tyres? Shitty mis-matched plastics? Correct seat cover? Nice levers?
Etc x1000.
Even knowing all of that, its a hard question to answer because very few of them come up for sale, especially the uncomplied A-models. Most that I've seen on Ebay have sold in the $600~$1000 bracket, with a nice looking rego'd one going for $1400 (or thereabouts - it was a couple of years back). So far, they seem to have absolutely no collector status, and are simply sold for their value as old dirt bikes "for ridin' in the bush and down me uncle's farm and stuff"...
I don't know whether the 83 models will end up being more valuable as they're the 'first of the breed' or will continue to be devalued by the lack of rego-ability.
If its a good runner that rideable, it basically has to be worth at least $350 or so, no matter how ugly/bodgy it is.
A pristine, 'as good as new' example would probably sell easily for a couple of grand - possibly quite a bit more if you are prepared to wait for the right buyer.
Everything else is somewhere in the middle, of course.
