Where: New Zealand: Taupo, Wanaka, Queenstown (amongst others)
When: During spring or summer. New Zealand is definitely colder than most people expect. Even in January and February the temperature can drop under 20C.
Price: I would say New Zealand is in the middle. Not as expensive as Australia, but not as cheap as one could travel in Thailand or Indonesia.
Get there: You definitely need a car to get to the most beautiful places. If you don’t want to drive you can try one of the hop on hop off bus company. They drive you everywhere and have many popular stops you can choose from.
Do: Have a wetsuit. Some lakes are glacier lakes and the water is freezing cold even in summer. So if you want to swim I suggest you’ll get a wetsuit to last longer in the water.
My tip: Beware of the ducks. They are vicious and definitely not afraid of you. I did the mistake and sat down with a sandwich… And it was gone immediately. So if you want to eat stay away from them. Unless you want to feed them, then go ahead.
DiemitdemGintanzt 
Amazing photos. The ducks in London can be bold, but not one has stolen a sandwich from me yet.