Hosted Payment Solution, or your own SSL cert?

Most payment gateways offer you two options, to implement your own checkout (within your site), or to use a hosted payment page (on their site).

Everything is set up faster if you use the hosted payment page, thus setup cost is also reduced.
SSL certificates are not cheap, and they require their own dedicated IP address. This also costs a few hundred dollars more per year.
When you host the payment page, then you are responsible for the privacy and security of the transaction and credit card numbers.
When a customer purchases from a familiar hosted payment page, they have a greater sense of trust giving their credit card number to a trusted bank, who in turn give some reputability back to the merchant. It's not easy for merchants to obtain merchant accounts from NZ banks.