we used Golden Arrow (they changed the dates to get us in before the quarantine regs came into force) and we brought two very old cats and our 5 year old dog. They boarded them for a month and therefore they did all the vet stuff (much better than dragging the pets back and forth), it also gave our girls an opportunity to get used to the crates there were to be flown in. It cost 4,150 GBP for the lot (boarding, jabs, flights) and was much better for our peace of mind. I couldn't leave them, even if we'd had to pay quarantine fees. I suggest you contact the quarantine facility in your intended location in NZ and they can give you an idea of what 10 days will cost so you can factor it in. For me, even though the cats are 18, I'd never have left them whatever the cost. It would have been a deal breaker over coming to NZ if the only option was to leave them.
I'm speculating but you are probably looking at 3-3.5k GBP (obviously this depends on the size of your dog and whether you have them boarded before (we actually found it was of little difference to have them boarded with GA and have all the vet treatment done there, than it would have been to have our vet do it, with the added visits and stress all around!!)
HTH