Unlike the professionally-run Armageddon conventions, the annual New Zealand SF conventions are held by volunteers in the New Zealand SF and fantasy community, and the guests are usually writers. All surplus monies go to charity.
There are panel discussions and many talks on how-to-write and get published., You don't have to have an sf or fantasy bent to gain valuable writing information. Where else can you have a nice fun-filled information-packed weekend so cheaply? Writers can make contacts and pick up tips at the con for a much cheaper price than if they were paying for, say, a full blown course at a learning institute or wherever. If you just want a taste, try coming on the Saturday only. You can probably buy at the door. Oh, and please don't think it's completely about people dressing-up and giving everyone the Spock salute. This con might be a bit too 'serious' for children.
http://www.aucontraire.org.nz/
Here's a pic I took at a national convention just after "The Lord of the Rings" had opened. It is of Weta model-maker Mary Maclachlan demonstrating some props. About, maybe, 20 years ago I went to a New Zealand annual con(vention) called Forrycon. There was this guest director, a barely-known guy who had just made his first amateur movie. He talked about how the movie had taken months and months to shoot. They had to do at odd spare times. He spoke of having to work around volunteer actors who had other commitments, and illnesses, and weather. Yes, yes, it was Peter Jackson, and it was at this con where his eyes lit up on one of Mary Maclauchlan's great model displays and he asked her to work with him.
There will be a Weta talk at the 2013 convention.