I had a look at the available material on this and there’s nothing much in the NT Act except that they unpaid levies are considered a debt that can be pursued through a tribunal if it’s below $10k, then you go to court, and ultimately the Supreme Court if the amount is enough.
The details are very slender on how much you can charge for the cost of debt recovery – one article even warns that the cost of the bailifs might exceed what the tribunals or courts are prepared to order as compensation.
FYI, in NSW and Victoria, you can charge the reasonable costs of debt recovery to the debtor, which has led to strata schemes employing specialist strata debt collectors as their services are effectively free.
Regarding the NT, this is definitely one of these cases where you would talk to an experienced strata lawyer before you committed to anything.