I buy & sell a lot on TM. I generally always use NZ Post, as they are the cheapest!
I have sent bike tyres.. & also a 4 person tent & 2 blowup airbeds in a parcel.. no worries.
Go to the NZ POst website.
www.nzpost.co.nz & look up their parcel sizes/prices.
According to the pamphlet I have in front of me now.. max cost for a parcel weighing between 20 - 25kg.. for within an Island, but over 150ks.. is $21.45!!

(how far is Hamilton to Upper Hutt??? as under 150ks is only $9.95!!)
Their max dimension formula:
length = 1.05m
length + girth = 2.5m
volume (length x width x height) = 0.125m3
Max weight: 25kg
Hope this helps!!
Jen

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