Trying to book for accommodation for a group of five can be quite challenging...
We weren't too worried about the quality of accommodation, just looking for somewhere to sleep that wasn't going to cost the earth. As such I checked out Arataki holiday park and found a motel room that claimed to sleep 10. For the 5 of us it cost under $200 for the night.
I must confess my expectations weren't very high, but as it turned out we were very impressed. The decor was a bit dated but it wasn't shabby and the level of cleanliness was very high. And the motel was absolutely huge, with (I think) 3 separate bedrooms plus more beds in the lounge.
It's slightly out of town, but chances are you drove a car to get there anyway.
The kitchen was well stocked (and they weren't mean with the hot chocolate sachets) and the beds were comfy.
The Arataki honey place is on the same street, I recommend getting some mini pottles of honey for breakfast.
In summary, if you don't care if it doesn't look posh and you have a big group of people this place is ideal and really great value for money.