Site conditions
Tight crawlspaces, mature landscaping, elevated slabs, and salt-air corrosion on existing hardware can all add labor before installation even starts.
What the scope should cover
Panel capacity, transfer-equipment placement, pad materials, and finish work should all be spelled out rather than assumed.
Permits and outside expertise
Flood-zone rules, historic-district review, and utility coordination may pull in a permit expediter or additional trade. Check current requirements with the provider and the city directly.
A range is not a bid
A number on a screen is not a bid. Insist on a written quote tied to your actual property.