'66 duetto roundtail spider

[simatron]

We have a '66 duetto roundtail spider in the family that is in pretty good nick which I am thinking of purchasing off my uncle, but cannot find any info on this particular model or any indication of price anywhere.  Does anyone know roughly how much a '66 roundtail is.  I believe it is a pretty rare car in Australia.
Cheers!
Sime