True, everyone is going to do the trail differently so setting out some likely costs is difficult. What I’ve done here then is give my own costs for the South Island, with enough detail that you can work out where you would spend more or less. I give a link to a spreadsheet at the bottom of this page where you can do your own calculations. Figures are in NZ dollars.
This is starting/finishing Wellington and includes the luxury of staying at Coleridge Lodge and the associated transport around the Rakaia River. Most people hitch-hike around the river and stay at a camp ground or hostel at Methven, which will reduce costs significantly.
Airport transfer Invercargill
Shuttle Invercargill to Bluff
Struan Flat Rd to Ohai (hitch-hiked)
Ohai to track start at Struan Flat Rd
Princhester Rd to Te Anau (hitch-hiked)
Te Anau to Princhester Rd shuttle
Shuttle Greenstone to Queenstown
Coleridge Lodge transport around Rakaia
Water taxi Ship Cove to Picton
Ferry Picton to Wellington
There are a few somewhat luxury accommodation items here that you could save on, and if you are a couple there will be economies possible per person as well. If you always stayed in a tent in campgrounds or hostel grounds in towns at $20/night you would be paying about $582 (including the fee for back country huts) for one person at all the locations below. So that would be about a minimum.
Invercargill hostel 2 nights
Colac Bay camping ground ‘cabin’
Te Anau hostel
Arrowtown motorcamp tent site
Wanaka motorcamp cabin
Lake Hawea Hotel room
Lake Middleton camp ground
Lake Coleridge Lodge
Boyle Outdoor Education Centre
St Arnaud bunkroom
Pelorus Bridge camp tent site
Mistletoe Bay bunkroom
Bay of Many Coves campsite
Furneaux Lodge backpacker room
The figure below might be more than many people spend, as it includes café eating (nice as a bit of luxury), protein powder ($145) and 20 pre-packaged dehydrated meals (purchased when on sale at about $11 ea). Plus an attempt to eat nutritious food on a daily basis. You could get by on packets of instant noodles in the backcountry areas and then eat protein, vegetables and fruit when you reach a town. But that might mean going off-trail frequently.
Café food – lunches, afternoon teas
Trail food purchased on the trail
Trail food purchased before departure
Postage of 10 food parcels
Te Araroa Trust donation
Washing clothes at hostels ($3 x 4)
Cellphone pre-pay top-up (2 x $20)
This is hard to put a figure on because it depends what you have already and what you buy specially. I spent about $1,200 getting new boots, light-weight wet weather gear, shorts, light-weight down jacket, water filter, extra hiking pole, new socks, tent fabric, new sunglasses, etc, etc.
If the figure below looks scary, other blogs suggest lower figures. Blogger Joe has it at $6000 for both islands (excluding pre-trail gear purchases). ThereIsnohorizon proposed $1000/month excluding gear, with $20/day for two people for food, and camping in towns. Maybe they were living on dried bread and water. Mick Beckers is not far off my figure, with $AUD $8650 (NZ $9040) for both islands with $15/day back country food and $50/day in towns, and camping extensively also. And Michael Deckebach worked out that his costs were US $30/day, excluding gear and airfares. So it is all a question of what level of comfort you desire and what you include in your calculations or not (e.g. gear, cost of getting to start/end points, side trips, extra stays in towns).
However, there is more to it than that. If you skimp on gear you could be putting your life at risk. If you don’t eat nutritious food, then that will eventually catch up with you. And if you stealth camp to save money then you risk damaging the good will of landowners that enables the TA to exist and thereby ruin it for everyone who comes after you. On that score, remember that the trail only exists because of goodwill, donations and many hours of volunteer work. You wouldn’t be walking the TA without all this, so give something back for that privilege and to make it even better by donating to the Te Araroa Trust.
Here is a spreadsheet for download you can use to have a go at working out your own projected costs, but bear in mind that there will be unknowns, particularly in the food department, where it is quite difficult to estimate costs, including just how often you will be tempted to eat out!