The minimum wage in Australia doesn't work the same way as it does in the US. Australian workers will under an award -- effectively a industry-specific contract negotiated by the respective union. An Amazon worker would likely be on the Storage Services and Wholesale Award.
This starts at $20.72 (14.92 USD) for fulltime, and $25.90 (18.64 USD) for casual work.
There's higher wages based on experience and responsibilities, as well as penalty rates. Public holiday pay starts at $56.98 (41.01 USD).
As someone who has recently moved from Melbourne to Boston; if anything I feel like Australia has a lower cost of living. According to the one source I found, prices including rent in Boston, MA are 36.53% higher than in Melbourne
A receipt in Australia for example will display total:$10 including $0.90 sales tax. it is illegal to display a price that doesn't include it.