Share 'Cheap worms in Auckland, NZ?'

Hi all,   does anyone know of any cheap worms in Auckland (central)? I have seen some advertised for anywhere between $30-46 but as I am making my worm farm (so far it has set me back all of $25) I was trying to do it for as little as possible. Thought someone might have some spare that I could trade some summer produce for.   Cheers,