Not with a bargepole...!
Do it like this: research what you want to buy, rent a car for a day or 2, look at at the vehicles that fit your expectations, have the AA do a tech check on the one that looks best and take it from there. AA will register the car for you, do a WoF/MoT and set you up with insurance ( which isn't compulsory in NZ - yeah, brainless.. - but highly recommended.)