In Australia, Target was given the exclusive on the much lusted after Gold Mario amiibo. Today it went on-sale. You can probably guess what happened next.
Incredibly, the online stock for the amiibo sold out in 15 minutes flat. An employee informed Kotaku that it has been completely removed from the online store to help avoid disappointment.
If you are still in search of the Gold Mario Amiibo, your best bet is in-store. It's difficult to tell which store has stock, since Target's central database is typically two days behind, but almost all store were given stock of around 20 to 100. When I called up, Target's customer service staff were extremely helpful, taking my postcode and then using that to help search for the nearest store with the most initial stock.
There's also an extremely helpful Reddit thread that gives the number of Gold amiibo sent to specific stores. You might also find that useful.
Good luck people. It's a jungle out there.