There are too many variables to provide costs without an assessment of the existing infrastructure arrangements and details of the customer requirements.

Yes. The energy providers have set fees for certification and inspection of projects performed by Accredited Service Providers. These fees are set by IPART (The Independent Pricing & Regulatory Tribunal).

Level 1 relates to construction of distribution networks. These networks are owned by the energy providers ie. Integral Energy, Country Energy.
Level 2 relates to servicing and metering. This is the connection between the distribution networks and the customer’s development.
Level 3 relates to design of the distribution networks by an accredited service provider.

Generally speaking underground power is considerably more expensive. Depending on the situation, a combination of overhead and underground power maybe the best option.

Yes. Depending on the nature of the project to be undertaken, other requirements could be Easements, Environmental Impact Assessments, and Approval from other Government Organisations etc.

Generally speaking high voltage relates to 11,000 volts in most distribution network systems. It is then transformed to low voltage (240 volts single phase installations and 420 volts three phase installations) for domestic and commercial usage.