building up hours

Aircraft hire charges are probably a better comparison - In NZ Dollars (inc
GST) for a PA38 or C152 you're looking at around $140.00 per hour max
(around USD 98) - you can get hour builders for, say, 20 per hour less, but
they tend to be a bit cruddy.

Personally, I've always made the effort to share the cost equally with 3
other friends - how does USD $28 per hour sound for a C172 - or USD $60 per
hour for a light twin sound

When she was there in Feb. it was $5 US equivalent a gallon and we
were around $2.00 plus change. It spiked at $2.40 and is back to
$2.19.

I'm not sure if I'm reading you right - you're saying that your wife saw
pricing in New Zealand equivalent to USD $5 per gallon? If so, that doesn't
add up - that works out at around $1.79 NZD per litre - hell, we even sell
it to the stock car boys (at a big profit) for $1.65. I was the one
responsible to setting hire rates on club aircraft during Feb - off memory
our buy rate dropped from 1.145 per litre to 1.105 - tax needs to be added
to that, but it's deductable for us, so no net effect. Multiply by 4 to get
US gallons and multiply by 0.7 for USD and that's the component cost of the
fuel in the hire rate.