That happens a lot in many segments of the population. When my uncle was detective, there were similar incidents among the orthodox Jewish community, as the cultural preference from the diamond trade was instant settlement. It’s also easier to move gold across borders. Many folks were hesitant to call the police which made it worse.
Prepper people get targeted alot as well. One dude in my hometown was a victim of a home invasion, held hostage and lost about $250k of guns, ammo and silver. You don’t hear alot of about this stuff because typically these communities are not exactly following the letter of the law from a tax perspective.