BROOK SABIN Twenty dollars doesn't buy you much these days — but it can land you a night hidden private island in Dunedin. Twenty dollars doesn't buy you much these days. Perhaps smashed avocado, if the café isn’t too pricey. You can't even window-shop in central Auckland for $20 – you need to pull out a small mortgage just to cover the exorbitant parking expenses. So, $20 for a night on a private island seems like a steal. And it is. Tucked away in the Otago Harbour is a little slice of windswept paradise, with a fascinating history. Welcome to Quarantine Island/Kamau Taurua.