Used ace automotive in Taupo, wasn't spoiled for choice they were the only place open!! They were good to deal with, gave me a good run down of what they were going to do and a pretty accurate estimate, checked how much refrigerant was left in the system and it was about 30% of what it should have, pressure tested the system with nitrogen and it held pressure so no major leaks, evacuated all the gas out to remove moisture then re-gassed it. Not sure on the value, it depends on how long it keeps working for I suppose, but it was just under $600. Worth it to have it working for the drive home!!