Total is $930 New Zealand dollars which comes out to just $699 US Dollars!
This seems to work for tons of dates in January and February. If you can find it in other months please post a comment!
Sample dates for JFK-JNB
Update: According to the Flyertalk thread on the deal:
Works for IAD as well. When AndrewT84 mentioned CPT works as well, I checked and there is the same (or noted +$) base fare to LAD, LVI, DKR, LLW, PLZ, ELS, VFA, HRE, BLZ (+$50), LUN (+$50), DAR (+$120), NBO (+$120), EBB (+$120).