There is no import tax, ridiculous laws, regulations or bans that apply to software.
As with most things sold here, there is a 10% GST applicable, but there are sales taxes applicable to the USA prices, and our $ is worth more than the USA.
Our wages (and cost of living) are a bit higher than the USA, but as already mentioned above, when you are talking about electronically distributed software, and no local support, that is hardly a consideration.
This is not a problem caused by govt, and one would hardly imagine them holding an inquiry if there were any chance it was. I recall a classic line from Yes Minister - Never hold an inquiry unless you already know the answer.