It's one of the things I genuinely like about Australia (despite being more on the "paying for expensive trades work" end than the receiving side of those wages) and also slightly mysterious to me - it's not like that "next door" in New Zealand, and I can't figure out why. It feels like a subtle difference in the class system, but some people say it's stronger unions. I can't identify any huge differences in labour market structure that would explain the discrepancy.

In NZ you have to own the business to make decent money in most trades.