I just thought I'd mess a round and looked up catching the train up to Auckland & spend a week up there in case both games were there. $318.00 return or $159 each way. Just for the train from the 15th to the 25th - ouch. Next I'll nosey at flights.
Always worth checking out transfercar, a car from Wellington, often with petrol, is usually available. Then train or fly back. Of course won’t be able to book a car til later in year or new year if looking for a deal with a free tank of petrol, some available now without the free petrol