What has changed since Muldoon?   
Crime. Not changed, exactly, just a lot more of it. Don't leave possessions in vehicles, don't wander quiet city places in the small hours. It is not frightening, you just have to remember that certain individuals prey on tourists.

I've bought bargain vehicles from departing tourists by making a low, firm written offer that was good for 48hours only. I bought a good Jack and Danny Brothers dreadnaught on Trademe for $82. I actually bought three guitars between $55 and $90, all usable, all Chinese.
A useable Fender/Epiphone is about $200 new.

If you need a local agent to take some pressure off, I live in an Auckland suburb, and I LIKE dealing on Trademe.