Insurance & overhead — Established companies cost more to operate.Real companies have real bills.
Warranty — Longer workmanship protection adds value.A promise to fix things later is worth money.
What's included — Permits, disposal and fixtures may be included, or extra.Some prices include everything; some don't.
Trades & systems — Labour quality and waterproofing methods vary.Better builders and better waterproofing cost more.
Project management — Some contractors coordinate everything; others don't.Someone has to organize it all — them or you.
A higher quote doesn't automatically mean you're being overcharged. Make sure you're comparing the same scope.
A bigger price isn't automatically a rip-off — just check both quotes cover the same work.