Man, in the US Craigslist is fuckin huge! Did you try Ebay?
If you go to the show, someone might be selling an extra ticket or something. I've shown up to a few sold out concerts with out tix and gotten in. At least you can listen from outside.
can't wait! btw if you melbournians are in the mood for a good warmup gig or two then my band is playing at the arthouse on the 29th of this month w/ the Eternal (who supported Opeth last time)and at pony on the 30th. should be great!