^ I remember the same thing happened a couple of years ago when a certain popular act came to Perth; my missus and a friend of hers tried for ages to get tickets for the concerts in Perth but all were sold out extremely quickly, before scalpers =whacked them on ebay. Thankfully tho the act announced more and more concerts in Perth to accommodate the huge demand, and my missus and friend were finally able to get tickets (albeit at 5pm on the day of sale) for the last concert.
Now while i abhor popular music and everything it stands for (or doesn't, as the case may be), i did gain some respect for the act for playing more shows (from memory about 5 in total in Perth alone), even tho their music makes my ears bleed and i can't fucking stand the sight of them. However it seems they found a way to beat the scalpers for once; by playing more and more shows they not only made more cash for themselves, but also gave more people who wanted to go the chance to see them anyway, therefore making scalped tickets not worth the hugely inflated prices they were asking on ebay and wherever. If that isn't worth a tip of the hat, i don't know what is.
Lets just hope AC/DC does the same; they have a massive fanbase in Aus, and if i were them I'd stay as long as possible.