This is not the problem.
You (and others) are making false-pretenses, and assuming everyone is out to dupe gold. Stop it. These people are out to kill townships, kingdoms, and ruin our fun as a community.
We could go as far as not restoring gold specifically if this is an actual problem, and still restore everything else. It's not like anything else is used for anything aside from building or PVP. IF people started duping diamonds for bans, A) there wouldn't even be a reasonable amount or it would be caught, and B) even if it happened over a long period of time, items still go down in price as more are on the map, and this would just mean we could see fancier structures and see a better built world in a shorter amount of time. ASSUMING every single case from hence forth would be ONLY to dupe and bypass the rules, and they would NEVER ever be caught becuase we are ALL slippery mother fudge packers capable of that. Yeah, get real. You are so toxic it makes me burn just reading your bogus texts. You are crazy if that's what you believe and you should check yourself and think twice. Be more realistic, and logical. Most of these people would not grief anymore if there wasn't a way to "win" by destroying others precious time, and valuables.
As symbolite said, everything is of worth, including the last stack of 64 cobblestone I just had.