Hi Fletchaman,
I'm a biomedical scientist working in the NHS, and I have checked with the professional registration body for my profession in NZ to see what the salary was, and it was exactly the same as in the UK.
I imagine it will be the same for a midwife. I think health care job salaries are pretty universal cus you are doing the same job wherever you go, so they pay you accordingly for you qualifications and expertise.
Have a look on the internet, just type in somet like 'what is the salary for a midwife in NZ' and you will find something.
I can't comment on your job because I imagine that all salaries in private industry are decided by the particular employer.