timbosan:
Very good point, although I thought basic back-to-back installs where closer to $500 (but a quick Google shows around $700 as the cheapest). Wasn't it DeLonghi that did the "quick connect" heat pumps a few years ago, which where pre-charged and simply needed connecting from the indoor unit to the outdoor? I installed one myself a few years ago. Are they still around?
I was looking for one of those as well as they were being sold on trademe. A little while ago someone on here said they were no longer available and gave a compelling reason why they were not going to be sold anymore. I can't remember what the reason was, however, at the time I accepted it as a valid reason and that I would not be able to get one anymore.
A bit of searching any you may be able to find it.
Edit - here your go. Reason was isolation not meeting nz reg.
https://www.geekzone.co.nz/forums.asp?forumid=141&topicid=237647