Giday Andy,
There are only a handful of the 'Timezone' type places now, unfortunately with very little or no pins.
BUT Melbourne is the Pinball capital of Australia. We've got some of the best dealers with quite a large stock of pins on site, ready to play (free yay!).
MarkC (PinballSpareParts) is in Bayswater (about 50min) from CBD and Bumper Action in CBD (one of the best looking showrooms ever! - they also hold weekly Friday night pizza / drinks nights). There is also Zax amusements (not far from Bumper) and BCW in Campbellfield (about 25min from CBD). Between them all is a huge amount of new (MarkC should have NIB Sterns in the showroom) and used pins...
