The thing is correct for exchange rates is pretty meaningless. All it says is how much $1AU is worth to an american, not how much its worth to an aussie.
A better way to do it would be to rank it on the relative costs of something like a big mac. Or as a fraction of GDP/capita.
I believe the cost of city living is roughly half what it is the US in AU.
In summary, the harddrive was fucking pricey.