How is it the NZ has been able to attract so many people to buy their good wines although the prices are high? Also, why are they so high?

I totally disagree with the premise of your question. Compared to what?

Most of their wine, especially their most popular and successful varietal Sauvignon Blanc is not high in price at all - generally. As far as price to quality, they are some of the cheapest wines around. NZ makes a lot of fruit forward, easy drinking (yeah simple, but it's a pretty simple grape) inexpensive but good quality wines.

I hate to generalize the whole country, but the other varietals like Pinot Noir mostly never seem to be more expensive than other areas. California Pinot Noir and Burgundy can be downright insane in price.

So that is why they are popular IMO

Sorry for being unclear. I was comparing NZ prices of SB with those of the Americas. The only written commentary about this I have read so far is from the WSJ from 2 weeks ago. I was hoping more people can shed some light on this.