You really expect someone breaching a contract to get away with paying less than what they owed by contract? In what alternate universe is this ever the case?
I'm curious about which jurisdiction you think this contract exists in, because you're sure as shit not going to get an award of punitive/exemplary damages under NZ law. Nor are you going to get an award for full costs (typically, only about 60-70% of actual costs are covered in a judgement where costs are awarded in Australia and NZ).
I don't agree with Joel's reasoning, but you're dreaming if you think that a NZ court would award you the amount you're trying to claim you're owed.