https://www.theverge.com/2018/5/31/17412736/amazon-blocking-australian-shoppers-imports-gst

Australian shoppers will find themselves limited to a much smaller Amazon item selection beginning on July 1st. Instead of being able to visit and make purchases from international versions of Amazon’s web store — as most of us can do — they’ll be redirected to the local Australian site. Geoblocking isn’t the only strategy Amazon is taking; Amazon.com and the company’s other sites will no longer ship to Australian addresses as of the same date.

When I say “much smaller,” Amazon’s local Australia site still sells tens of millions of products, but it’s definitely a significantly lesser total than you’d find from Amazon’s US site. Reuters estimates that it offers one-tenth of Amazon.com’s selection. All the basics should be readily available, but this will be a real problem for certain item categories.