The hunting shop in town has the 420HC for US$140 and the S30V for US$250. Other shops are more expensive.
possibly has to do with the higher disposable income of people in NZ
I'd say you're bang on, especially with the first two points. As far as being the most successful nation at keeping out germs and invasive species.... I'm not sure. We definitely try these days, but organisms introduced in the past have caused a lot of damage and we have lost a lot of species.
What I basically meant is the process is probably the most successful in the world at currently keeping new harmful organisms from entering.