Tell those bureaucrats to go get fucked.
There's no need to pay GST on import for under $1k. The whole reason they put it on the retailers is because it cost more money to collect those GST than what they make out of it. So if a retailer ship stuff under $1k and the GST is not paid, then what? Anything they do at that point waste money.
If they stop items under $1k, a shit show will immediately be staged on social media and their election will fucking burn.