The Delta variant is ravaging NSW, and there are no signs of the Delta outbreaks in Melbourne getting under control, either. This variant is so viciously infectious that there is no room for any error or "let's wait and see if this sniffle is anything but a sniffle" or "I'm a sovereign citizen and I want my freedom". If we were all 100% compliant, I could see Victoria snuffing out these outbreaks, but if the compliancy is even 90%, it's too little to control Delta. E.G., there are persons working in the Sunshine area as essential workers who are infectious, but who have not stepped up to be tested. The wastewater results make it clear. It only takes one person to ignore the call to get tested, or to ignore a runny nose (on the grounds of "Meh, it's just a runny nose") for Delta to beat us like cake batter.
All of this means that ... yes, throughout all of Greater Melbourne (and through regional Vic as well), we are in severe lockdown; we can't try on shoes or clothes, which is just another ongoing frustration in all of the many frustrations that lockdown imposes. Online purchases are the only ones we can make.
However, we can still purchase from the big shops / shopping centres / local stores, and in many cases click and collect is available. (REAL click-and-collect, not eBay's weird idea of it.) Authenticity won't even be an issue if you purchase from a recognised authorised footwear or sportswear seller. dave's advice about avoiding risky purchases online is really based on avoiding those purchases through unknown and possibly unauthorised sellers on eBay or other online marketplaces rather than through the big box sellers' own websites or their presence on eBay. (And of course he also mentions the benefit of actually trying on shoes or clothes. While we can't do that in Melbourne during this latest horrible lockdown, almost every clothing or shoe seller that I know will accept returns for items that, when you receive them, do not fit, and we can then ask for the next size up or next size down (as appropriate) to be sent. Australian sellers really are doing everything they can in most cases to help buyers deal with the restrictions.)
As long as the seller is a legitimate business in Australia, with an ABN and good reputation, authorised to sell the desired sneakers, the purchase is not going to encounter the difficulties or delays that you've mentioned, OP. Of course, your purchase could still go smoothly (even if there's a delay) - but buying online, especially in a pandemic, means that you need to accept that there will probably be delays because of the very thing that is driving more people to buy online at this time. C'est la vie.
