Yes, it's unfortunate that there is a huge difference between inbound and outbound fares but, as WHBM mentioned above, airlines originating from NZ can charge whatever the market wil bear. It's the price we pay for being so remote and the lack of competition.

You may like to check out the following link -

http://www.cheapflights.co.uk/flight...urch/Heathrow/

However, these fares will be heavily discounted and probably no chance of being able to change the return date without heavy penalties and even an upcharge in the ticket price.

Occasionally we see OK fares on special from NZ to the UK - the fares I see the most are from Air NZ and Singapore. Again, probably not a lot of flexibility.

Hope this helps a little and I do suspect you'll be able to find better fares than those quoted in your OP.