Any nonturbo sedan for over 5k had better be MINT with low original miles and working everything.
Don't worry about losing it. He won't get 6k even if the motor is a rebuilt. You've still got 260k on the transmission, differential and driveshaft, axles and suspensions rubber.
Good luck to him, but really, if your budget is 4500 you will find a great example of a sedan.

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