Re: I may buy a brand new JEM but...
The JEM is an incredible guitar. You'd be lucky just to have the opportunity to own one. Most will never get to.
Now regarding the gold coming off the bridge. Uh, yes, it will "eventually" come off. Study the 2nd law of thermodynamics and increasing entropy. In layman's terms it's the fact that ALL things in this universe degrade. So, yes the gold will come off, ...eventually, lol. Unless you just want to buy it to look at and keep locked up in a showroom case. But, ...do you ask this question before you buy anything else? This is the last thing you should be worried about IMO. The other's posts about this are accurate regarding cleaning and palm moisture.
Just remember, ...if that's your standards for buying something uber sweet, ...you'll never own anything uber sweet, lol. Like, a house, a fine car, ...whatever.
Hope that takes that issue out of your equation and makes your decision way easier. If you like the way it feels, buy the thing and play it till the wheels fall off! (okay, ...this only applies to cars but you get the point) The trem is a gem (yes, bad pun, i know) and the pickups are insanely versatile for cleans and distorted tones. It's just one of the best guitars available in the world, IMO.