I'm from Melbourne - Forget hotels, you can stay in a great hostel for USD$39 (AU$59) a night here, which is very affordable, and an amazing way to meet people. Don't be afraid of dorms, I've literally had the best times of my life backpacking the world and staying in dorms. Here's a hostel in St Kilda I'd recommend that's $39USD/$59AUD a night for a 10 bed dorm (which isn't too big, avoid huge dorms >18 people) https://www.hostelworld.com/pwa/hosteldetails.php/Nomads-For...
You will get more than accommodation. You will be welcomed in to a group of young travelers from all over the world who are looking to seize the day.