Solar installer costs are usually included in the overall price of a solar system, rather than charged as a separate fixed fee. The amount can vary with system size, roof access, switchboard upgrades, scaffolding, travel, battery installation and any extra electrical work. Ask for a written, itemised quote covering GST, installation, approvals, meter changes, monitoring, warranties and after-sales support, then compare several qualified installers. Check that the installer is appropriately licensed and accredited, and confirm any rebates or incentives through the official government website before signing.