Actually, Dungeon's been wanting to play WA for a long time now and we were even offered some shows about a year ago, but the sad fact is that it's actually more expensive to tour to Perth than it is to Japan!
In Japan, we know we'd make our money back even though it may cost more initially to get there, but with Perth or anywhere in WA for that matter, we'd be down $2000 at the very least before we stepped foot onto a tour bus or flight.
It's relatively cheap to do Sydney -> Melbourne and there's a guaranteed crowd there, which is why most bands that come here only play those 2 cities. Kinda fucked, but that's the reality of it all, sadly...