Builders make about $100 an hour. Not sure if they pay tax or not. I'd imagine most trades pay tax on some jobs and not on others. Trades are not the only areas where people evade tax. What about "cash only" down at the food court?
These days you can get a dongle that does bluetooth to your iPhone/Android and this allows you to tap your credit card on the phone. I've used this, it works better than eftpos. (this is what credit card skimmers use on the subway in europe btw).
The issue isn't the trade, the shop or the person. The issue is the Australian Government and it's inability to do what needs to be done. It's all about getting re-elected, our system isn't working.
This is how it should run:
1. ALL businesses must use either an eftpos machine or smartphone dongle equivalent.
2. Cash phased out.
The result is that everyone is forced to electronically record every transaction and crime decreases.
The reality is that with an ageing population the current slice of taxpayers can no longer sustain the burden. The net needs to be widened so it includes everyone the same way it does the wage earner.