Otago is the second best university in New Zealand(first is Auckland). I don't think it's too hard to get into, especially since international students have be pay much more than New Zealand students. I looked around for you and here's the tuition info: http://www.otago.ac.nz/international...NZIntlFees.pdf
They're all in NZ dollars(which is down at the moment) and the current exchange rate is about 1US dollars for 2NZD.
The school website is http://www.otago.ac.nz
if you want to look around for more general info. =)