I would strongly advise against importing a single game unless you are fully aware of the costings.

$4500 for the game ? 

Add GST for the game
Add Import costs -Customs clearance and paperwork
Add Freight forwarding fees
Know that there are tariffs that can be applied to save you paying 10-20% duty
Add GST for all the costs.

I bought a single game from Germany that I bought for AUS$1500

To my door, the game ended up (in total) to be AUS$2800 - $1300 in costs.

It will cost you a lot more than $4500.

There are so many dealers in Melbourne - at least FIVE places to visit and compare quality and price. Use that to your advantage and shop around. DO NOT buy the first one you find.