Im in QLD, so not sure how exactly the laws are different. But when I broke a lease start of last year it cost me, a 'lease break fee' - worth 1 weeks rent plus 10%, a 're-listing fee' for them to advertise the house again, and cover costs of them signing a new person. I also had to continue to pay rent until a new tenant moved in. All up, breaking the lease cost me nearly $2000.