Are the proposed systems comparable?
Check the exact generator, transfer equipment, fuel arrangement, covered loads and control options. Two proposals can look similar while still covering different home needs.
If the system design or load coverage differs, the prices are not apples-to-apples.
Which site work is included?
Look for pad or base work, wiring, fuel routing, meter or tank coordination, permit and inspection responsibility, and restoration. These are the details that often change the true scope.
If a proposal does not say who handles a task, treat that task as unresolved until it is written down.
Who supplies warranty and service support?
Ask the actual supplier or installer for the equipment warranty terms and any separate workmanship or maintenance terms. Confirm who provides support, what is excluded and whether there are conditions you must meet.
Keep those terms with the proposal and the eventual work records. A brand name or a verbal assurance is not the same as the written support offered for the equipment and project.
What should be clarified before booking?
Clarify exclusions, payment, schedule assumptions, commissioning and owner training before you book. Those are the points that most often change how complete a quote really is.
A clean decision comes from knowing what is included, what is excluded and who is responsible for each remaining piece.