Rats ruined multiple wire harnesses in 98 Caddy Deville. Whats Cost to repair?

98 Cadillac deville base model. One owner till I gave it to grand daughter. 168000mi. Run great till parked out side and not driven for two weeks. Pack rats chewed up extensive wiring. How much should it cost to replace engine, dash , body and headlamp wire harnesses. I'm not sure if they all need replacement but they might. I see on the Internet there are lots of used harnesses available for 400 to 1000 dollars for all four. HELP!!