Not only is birth control expensive in NZ, you have to see a doctor twice a year to get it (for anything other than condoms), and they are expensive too. Tubal ligations are fully funded, but there is a waiting list and they are more dangerous, more invasive, and more permanent than vasectomies (which are not funded, unless there are exceptional circumstances).
On the flip side of the coin, fertility treatment is easier to get if you smoke, if you or your partner has been voluntarily sterilised and changed your mind, or if you prefer not to have sex with a man. A couple that has no specific, diagnosed infertility has to wait five years before they can get help, making pregnancy and birth riskier, and the parents five years older.
So, in New Zealand, abortion is actually cheaper to acquire than any other form of birth control. There is no safe, reliable birth control for any woman who eventually wants children, but has anything wrong with her intestines at all (or indeed for teenagers who routinely drink too much, shag someone random, and throw up their pill). On the other hand if you want to get pregnant, you should make some poor choices there, too.
Frankly, I agree with the handwringing politicians, that New Zealand does need a unified approach to reproduction, including a review of the old laws, but since these things cost money (and NZ doesn't like to spend money on women's health), and they might get the government voted out, I'm not holding my breath.