[seb]

One reason: the US prices don't include any sales tax, while the NZ prices do.

[mattdw]

This. Exactly this. I once looked into getting a friend to get a Macbook from the US for me; by the time taxes were taken into account it was going to be no cheaper at all – and if I took my GST write-off into account, the US import would have been more expensive.

[bloodnok]

Almost this.

$2870.00 * 1.15 = $3300.50 $3300.50 < $3799

(We have a 15% sales tax that also applies to items ordered from overseas over a certain threshold)