Compare quotes on the system size, panel and inverter brands, estimated annual generation, installation inclusions and any battery options—not just the headline price. Melbourne homes can have different results because of roof orientation, shading, weather and local network requirements, so ask each installer to explain their assumptions. Check whether the quote separately shows any Small-scale Technology Certificate (STC) discount, warranties, monitoring, electrical work and future servicing costs. Use a suitably accredited, licensed installer and confirm the final design, approvals and incentives with them before signing.