A lot of it depends on the cops and how you react to thier questions. In the NT you find cops can be very leniant towards small quantities of 'party drugs' found. Most people will get rehab options. If your a complete wanker to the cops well they will definately see you get the biggest fine possible.
Just let them do thier job, don't lie.
I had cops find a small quantity of marijuana on my porch which unfourtantly wasn't mine but I was lucky enough to be home at the time. Just wanting to get rid of them (and not wanting them to come inside and search the house) I admitted ownership of the pot. They tried to scare me into giving out my dealer saying I would get a criminal record etc.
In the end all I got was a $200 fine and they left me alone.