Holy ****!
www.shareeverything.co.nz
Share Everything plans starting from $69 for unlimited calls, texts, and 1.5GB data. Extra users can be added for $20/month (if signed up during promo period - normally $29/month), up to a maximum of 3 additional users.
So for $69 + ($20 x 3), you could have 4 people with unlimited calls and texts, albeit with a minuscule amount of data.
Can't wait to see the price wars from the other two!