Compare more than the headline price: check the proposed system size, panel and inverter brands, estimated annual generation, installation scope and any extra costs. Confirm whether the quote includes GST, government incentives such as STCs, switchboard upgrades, monitoring, approvals and grid connection. Look for clear product and workmanship warranties, and verify that the installer is appropriately accredited and insured. Solar output and savings are estimates, not guarantees, so compare assumptions and ask questions before signing; an independent energy adviser can also help assess competing quotes.