The main issue in NZ has been bank support to facilitate the exchange process -- I'm not sure what bank cryptopia use, or whether they've had their accounts closed at the banks they bank with. Most banks in NZ have (officially) stated that they have no problem with people purchasing and selling bitcoin for personal use (lie), but they state that they will close merchant accounts if they are discovered.

Cryptopia however have allowed NZ dollar to Bitcoin and back for the last year or two. There is another exchange launching soon that is also claiming to have partner bank support and will allow for margin trading to reduce the spread in NZ.

Overall NZ has pretty easy capital controls -- though many government agencies have yet to state a firm position on cryptocurrencies and the way that they should be treated. As it stands, NZ is about the most economically free country in the world... but... somehow NZ just elected a woman who has promised no end of new taxes, and spending / entitlements (minority government that won 35% of the vote in coalition, the largest party who got 46% of the vote are in opposition). To be honest I'd expect nothing less of clueless politician that hasn't done anything after 3 terms in parliament, who only 9 years ago was leader of the Union of International Socialist Youth. So it's likely to at least become a lot more onerous. An example is we don't have capital gains here... but see how long that lasts now.  I believe the new government are not as likely to be quite as friendly toward cryptocurrencies as the prior socialist-lite 'conservative' party.