your best bet mate would be to check out this website
it has pretty much all the lans in melbourne that you can go to (other then private house lans ofcourse
)
the website is a bit screwed at the moment but at least you get the names or all the lans and posibly web addresses (it is also the site most of the lans use to get players to register on for events)
http://www.ausgamers.com/events/if it is too broken let us know... perhaps someone who has a bigger mental capacity then me can list all the lans and site to go with for you
respawn costs $25 to go to, this includes entry to ALL the respawn run competitions and most of the time a significant amount of free food (usually a bbq or 2 and some late night snacks)