Kyanar:JimmyH:
Part of the problem is that I doubt there will be any extra revenue to do anything with. In fact, there may even be a substantial (net) loss of revenue. The current threshold for tax collection was set at $60 (=$400 purchase price when no tariffs are involved) for a good reason -- because collecting tax below that amount costs more to collect than they get.
If they try to collect GST on $20 purchases like the aussies are mooting then when I import a $20 item they will need to be able to intercept it, check the value, securely warehouse it, invoice me, collect the payment from me, and then speedily release the item. In return for which they collect the princely sum of $3 (=$20 x 15%). I can't see that $3 remotely covering the costs they will incur in getting it.
That's $3 plus $47 biosecurity levy, plus $46 customs broker fees, actually. Net result is that you will pay more in fees than the product cost - literally.
We don't know if the biosec and broker fees will be charged for low value items. They may well be exempted for low-value items that have a low risk profile. I suspect the government would throw the consumer a bone on that one.