Great advice here from Nino.
There are so many catches to importing a machine/s. About the only thing that you shouldn't have to pay is duty under the fair trade agreement between Aus and the US - this is where a customs broker would help out. The machine MUST be described as a coin operated machine made in the USA - I can't remember that actual wording exactly but it was something similar to that. Then you may or may not be hit with a customs inspection fee, fumigation, quarantine inspection. You must ensure the pallet it is shipped on has been treated e.g. heat treated to have a chance of sneaking through quarantine. Every time the shipping company or wharf looks at the machine they will charge you for it - fees to unload the machine and then fees to move it to the warehouse, then the machine has to be picked up within a certain number of days or there are more fees.......fees, fees, fees.
I have done it once. I imported two machines from the US. It was a great learning experience but would I do it again - NO. Not unless it was a very very special machine at a great price that I couldn't get over here. Nowadays with the numbers of machines pouring into the country, chances are the machine will surface at some stage.
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.
