After a few minutes of checking they came up with $3000 return per person Christchurch - Orlando for Dec 2020 which seems somewhat expensive again compared to previous journeys to same location. She did however say they will match the listed Air NZ prices...
In economy or premium economy?
$3000 for economy seems a bit steep.
You could try visit flights.google.com to find the dates & flights you wanted, then with all the flights' information go back to the TA to have them book the tickets.