It is up to you and the buyer to arrange payment and shipping. As a seller, you must make sure the item you are shipping is packed suitably to avoid any damage. If an item arrives damaged you are obligated to resolve the matter quickly and amicably with the buyer.
For items located nearby the trade will often be cash on pick up. We recommend you find out the costs for sending your item around New Zealand before listing, as this helps potential buyers budget for the delivery.