Marketplace
Skinny Broadband offers a 4G modem for home use at a cost of $99($49.50 with this deal), they have a $55 a month plan for 60GB data on the 4G network(Spark). Additional data is $20 per 10GB.
No term contract and you can return the modem for the price you paid if you are not happy in the first 30 days, they don't refund the plan cost in this case.
The most competitive low end offer right now for home broadband is flip.co.nz with 40GB ADSL and phoneline for $59.95 a month on a six month contract and BYO modem.
I am a subscriber. Was initially put off by 55GB cap but you can renew immediately. Very satisfied. VDSL unavailable and delays with fibre so this was our only option for fast, reliable internet. Slightly pricier than other options for our medium usage household - use a whole plan about every 15-18 days - so still under $110/mo.