Quoted from GreenMarine:What's the benefits of buying NIB?
Getting the game first. However in the case of a 2013 title like Metallica - zero reason to go NIB unless you ran out of patience trying to find a used one.
Sorry about your experience. I think the best you can hope for is that Stern may send you new cabinet decals. I'm sure you don't want to re-decal your game, but at least if you sold it in the future, they'd be there for the next owner if the scratches bugged them.