I'd love to buy a nice Fathom, totally in the market for that specific title, so I can speak just for myself as a buyer. I'm not paying an extra $1k for a new cabinet and another $1k for the "rarity and appreciation". It's still what it is, a nice 1980 Bally. It's only worth so much as an old game to me.
Maybe other people feel differently, but once you leave the $4k range I'm gonna pass for something else. Doesn't matter how nice it is (unless we're maybe talking HEP) there's just a point where you don't get your money back out of a game. Especially the labor. That's just part of the restore game for the most part, for better or for worse.