Both the local and international student pay school fees in New Zealand. Depending on the number of subjects you need to take, the fees can mount up to approx. 3,000 to 6,000 euro per semester. The costs are less after local rate for students taking a PhD. The school fees are paid to the university before the semester begins, typically twice a year.
In addition to the school fees are the cost of housing and as living, such as rent, food, books, travel, phone, etc. It is difficult to make a precise calculation, but on average you can expect living costs to be a about 15-20 % lower than in Europe.
Some universities offer scholarships, so good grades from previous studies can be a benefit. It is also a good idea to apply for scholarships from different associations. You may also apply for scholarships at your university, if you want to study for one to two semesters.
If your studies lasts more than 12 months, you can also apply for a work permit so you can work for 20 hours per week and full time during school holidays. Working while studying is an excellent way to get some extra money and at the same time to get some work experience. However, please note that your studies will take a large part of your time, so book your first semester for your studies until you know how much you will be able to work. According to former exchange students finding a job should be relatively easy.