Incorporation as a Charitable trust with the Companies Office is free.
Incorporating a society incurs a fee of $88.89 plus GST (see this site)
If you qualify registration as a charity, registration with DIA Charities itself is free.
Once registered with Charities organisations are required to file an ANNUAL RETURN for which there is an annual filing fee (currently $51.11 if filed online and around $72 if filed manually ) if your turnover exceeds a certain level (see the Charities website for current details).
Lawyers and consultants may charge for undertaking the registration of your organisation. Fees vary considerably.
Our consultant will be happy to advise/assist for a modest fee