Ahh..i think given that sydney hosts the mardi gras, sydney would be poof central!!
I love Melbourne better than Sydney!! much more interesting stuff to do and cheaper than Sydney. They actually had a thing about it in the news a few months ago or so saying that Tourism NSW are doing urgent advertising coz melbourne is now better and much more popular than Sydney so there!!!
I was going to suggest Nomads backpackers on Abecket street, but obviously since you are not 18 you couldnt stay there unless you had parents write a letter to the owners. But when you turn 18 its a great place, nice and clean though the toliets down stairs in the main entrance have a very small area, and a glass door looking in which isnt really good. But the dorms were really clean, but squeeky, like any bunk beds. Right next to the Vic markets.
i cant wait to go back to melbourne!