Owen
Sounds good. Two mates came back from OSK having ordered RV, now their fun begins.
Dr
There are other options to day VFR than NVFR. There may also be some charter and IFR operators out there who have enough trouble making ends meet without spending a cent on anything beyond essential maintenance. I've seen a few such aircraft, met a few pilots and owners, and I think we have a way to go before the majority of the fleet is fitted with even one, much less two, GPS that meet the TSO.
C100
The problem is, as noted during yesterdays debate, the good Dr has not read the JCP or its associated cost benefit analysis. The backup network is well covered therein and on overnight reflection I understand why the good Dr was so confused yesterday.
Australia has gone down a similar path to NZ but we have one inhibitor you do not - a whopping great outback and sheer comparative size between the countries. To expand, by my calculations (which could be wrong) the Oz State of Victoria - which represents about 3% of Australia's land mass - could almost fit NZ in whole. By my reckoning I can fly from end to end of either of your two islands on a tank of fuel
Therefore your backup navaid network can be considerably reduced on ours. It would not be so difficult if our outback was unpopulated - but it is alive and well and is well served by general aviation, who require navigation backup.