It's possible they wanted it for themselves, but I know lots of addicts who steal shit because they know it is expensive, only to have trouble selling it later

It's possible they wanted it for themselves, but I know lots of addicts who steal shit because they know it is expensive, only to have trouble selling it later and then dumping it. OTOH I've been privy to some "don't tell anyone about what I'm about to show you" moments from a group in LA that liberated some treasures from an institution that wasn't properly preserving them. Some places will let you check out even very rare items on a short term if you pay a deposit (sometimes hundreds to low thousands, a tiny fraction of the item's worth) and then you just tell them it got stolen and lose your deposit.