Get a new one about Aus$25,000, there's people replacing their 5.8's every couple of years so good supply of two year old boats about Aus$17000, three brand new Nacra 5.8's launched in the last 4 months with about 30 expected at the Nacra National titles at lake Cootharaba near Noosa Queensland over New Years. I've got a boat to lend you on your sailing pilgrimage or you can have a shot on all of them. Here's another video from about 6 weeks ago that shows the New 5.8 sails in the background and me giving my wife a thorough rinsing
https://youtu.be/IgcT5PaEKU4