Unless the rules have changed since I did it, some time ago admittdly, you will need the equivelent of £2000 showing on a savings bank account statement and have had it there for some time (3 months is recommended) when you send in your application or you wll have thrown away the application fee. You could borrow some cash off someone for a while, but again it must have been in the account for an extended period of time, not just three days.
I would strongly suggest, if you have been earning more than $45,000NZ in the last 12 months, have a degree, are under 28 and have been working for 2 years or more in a job that requires a degree, to go for the Highly Skilled Migrant Visa. You can work as long as you like then, and will be much more atractive to employers.
You can calculate whether you may be eligible on the website:
http://www.workpermit.com/uk/hsmp_calculator.htm