Obviously, per definition a collector is probably a watch nerd.

But I think the point is that if I want to transport money from one country to another, I can buy a watch for 30k, take it to the other country, and sell it to a collector relatively easy for probably the same amount of money.

Same if I wanna give a bribe to somebody, I can give them a watch for worth 30K and they can easily sell it for cash to a collector for 30K.

So that person would not be a collector. They would just use it to transfer the value.