In general, your average electrical switchboard upgrade will cost anywhere between $900-$1500. This is the price before any service disconnections or, Level 2 electrician work.
If you require any of the extras like replacing the asbestos panel, upgrading your consumer mains or any metering work, this will come at an extra cost. The below is a rough guide:
Up to 5 circuits/poles + main switch = $900 (including GST)
6-10 circuits/poles + main switch = $1100 (including GST)
11-15 circuits/poles + main switch = $1300 (including GST)
Anything bigger should get an individual quote