If I want to see Sanghai City, Do I need visa an dhow much cost and time it will take?

If you transit less than 24 hours, you needn't apply for any time. Otherwise, you need to apply for a transit type in advance. Normally, it takes four working days to deal with your application. By the way, you should apply from Chinese embassy in New Zealand directly because you don't have New Zealand passport. The cost is $60.