Right. I don’t know where you got the $1000 figure but all this game likely needs is a cleaning, new rubber, and flipper rebuild. Probably
Looking at $100 at most in parts.
If you think you need to pour $1000 in aftermarket crap on the game that’s up to you but you seem concerned about resale price - you will lose money when you sell it if you do that. Nobody ever gets all their money back on “mods.”
They don’t make Metallica any more and it’s a popular game. I’d say $3800-4500 is probably the right range as it sits depending on how badly you want it and how generous you are.