NZ itinerary - questions!!!

that budget seems fine to me for car hire, fuel, food and accommodation - have you considered the excellent NZ hostels? Look at the bbh.co.nz site for prices and reviews. It is peak time so almost everything needs booking ahead anyway. That way you don't have to buy the gear.

the DoC campsites are indeed cheap, but basic - pit toilet, usually not much more. Many of the popular ones will be booked out by now.

there are also smarter sites with showers and camp kitchens.

for quiet, choose smaller hostels and make sure there is no on-site bar.

Speaking only for the bit up north and Coromandel, you are going to have to book anything really soon as both areas are popular with locals (also peak time in hostels) and get pretty much booked out during that period.

Of course you do not have to camp every nights; nothing to stop you using hostels one night in four, for showers, laundry, beds, etc. But it is a popular time of year, you'll need to book some things soon.

Good basic plan, but a lot of driving involved.

I was about to exit for the evening when I saw then onto Tauranga. (Possible vineyards?!!!) which was surprise to me as never heard of a vineyard there. Googled it and yes there is one, LOL.
Tauranga is famous for Kiwifruit orchards though, mainly around Te Puke, which is on the way to Rotorua.

However, I'd keep the vineyard tour till the south island which really does have famous ones ( and really big ) next to the main road south. OK, just realised that you're not going to be north of Christchurch, so perhaps a tour in Tauranga, but don't stay there the night.
Actually, I'd skip Tauranga altogether and head to Rotorua.

Personally, I'd get out of Auckland as fast as my motor could take me. The only thing I like about Auckland is seeing it in my rear view mirror as I get the ** out of it.
Northland is great though. Loved that.

Coromandel is scenic but fairty rugged and better for longer stays at the beach than what you have time for.
I love Hot Water beach. Stayed there many times.

South of Auckland, I'd just do Rotorua and then see the Tongariro National Park from my car window as I passed by to Wellington. About 6 or 7 hours from Rotorua, or a bit longer if you stop off somewhere. OK, I see that you are going back to Auckland from Taupo, so forget the Wellington bit, but Taupo to Hamilton is pretty boring, as is Hamilton. I used to live there and I can't think of anything worth seeing on a short tour.

The south island is the gem though. Fantastic scenery, and don't forget the West coast, wild and rugged.

I'd go south from Chch and back up the west coast, not anticlockwise as you said. If you can manage it, the Tekapo area is spectacular.

#3 Good basic plan, but a lot of driving involved
Yes, a lot of driving. Many loooooooonnnnnnnnggggggg stretches without any sign of habitation depending where you go in the south island.

I went to New Zealand in January this year for 3 weeks, and am going back on 3rd Jan 2014 as it was so fantastic there I felt I did not get to see and experience enough of it! I did learn some lessons though, one of which was that I did the right thing in booking accommodation and transport in advance as it is a time stealer trying to organise things while away (although I do like a bit of spontaneity too). This time I have bought a YHA card, not just to get the discounts on the hostels and activities, but also to get the free wi fi, and so that has saved a fair bit of money too.

Not sure if it would be possible for you to take the ferry from Wellington to Picton if you have already booked flights? but was wondering if you would get charged excess baggage for all the camping equipment you plan on buying there - depending what airline you fly with I guess. Also, would it work out any cheaper to camp if you have to buy all the equipment as hostels can be reasonable prices, so not sure if it would work out the same. I looked at the doc huts for this coming trip but that was when I was thinking of doing 3 or 4 day hikes, but am now going to do just parts of the trails so not sure if you have looked at any of the more well know trails and doing part of them; for example, doing a day walk on the Kepler track and returning to Te Anau to a hostel?
The destinations I have for the South Island are: Christchurch, Twizel (for Mount Cook), Queenstown, Invercargill (for Stewart Island), Te Anau (for fjordland), Fox and Franz Josef Glaciers, Nelson (as a base for Abel Tasman).. The only things I am missing are both popular are Kaikloura and Dunedin, but have been to them before. Queenstown is fantastic for activities and hiking, so may be a good place for you to spend some time.

oh, and I forgot to mention that in regards to the Matamata Hobbiton tour, I read the reviews on Tripadvisor (which funnily enough I don't usually do), and there are a lot of comments about it being expensive for what it is with the consensus being it is more ideal for hobbit fans. The cost is currently NZ $75, and apparently the tour is around a farm and a lot of the set has been removed with one hobbiton house available to go in. Not trying to put you off, that would be hypocritical as I still have a bus ticket to go to Matamata in case I definitely decide to go there. If you don't go to Matamata, there is also Waitomo Caves on the Hamilton Route, and they are very popular too.
In terms of budget, it worked out at £100 per week for me for food, drink, laundry, tips, internet, etc. It did not include accommodation or sightseeing. I have looked through the various activities on both islands, and worked it out at £800 approximately depending on how many of them I end up doing.
Hope that gives you a bit of an idea.:)

We were in the South Island in 2012 and going back soon. We're older than you, but adventurous:) check out the holiday parks for camping with a kitchen/ showers. Also BBH hostels with over a 90% rating were consistently amazing.
N

We were in the South Island in 2012 and going back soon. We're older than you, but adventurous:) check out the holiday parks for camping with a kitchen/ showers. Also BBH hostels with over a 90% rating were consistently amazing.
N

My husband and I spent 6 weeks on the South Island in February/March 2013. I agree with everyone that the hostels are very nice everywhere, and you can get private rooms in some of them also. If you're interested in multi-night trekking there are quite a few trails with huts on them. We did a lot of multi-night hiking but did not carry a tent. The huts are typically $10-$15/night, or you can buy a hut pass at the DOC office (last year it was $92 NZD for a 6-month pass, which was WELL worth it for us). You'll need to carry sleeping bags, a basic campstove, camping dishes, your food and clothes and personal gear. I wrote about some of our hikes in my Christmas letter this year, which is here on my blog: http://www.lilyannfouts.com/holiday-letter-2013/

If you want to do one of the Great Walks be sure to make reservations well in advance.

Don't try to do TOO much...pick 3-4 things you really want to see and then relax in those areas and see the many other things each area has to offer, or you'll just go crazy just trying to race from one thing to another. Have fun!