"I see you have a lot of money. Based on that, I suspect that you are a drug dealer. Since you are a drug dealer, I am going to confiscate your money. And there is no recourse for you to get it back. Have a nice trip."
They will have difficulty getting away with that if you have two things: first, a receipt from the place where you bought those coins, and second, a bank withdrawal slip or check, showing that you purchased this from funds that you had in the bank. That might not stop the original confiscation, however it will make it much more likely that you will be able to get them back.
Of course, I think that it would also be very wise to have the particular regulations, whether they be from the Treasury Department or some other department or agency, which specifically speak to how gold coins are valued. They really will have a difficult time flouting their own employer’s regulations.
>>”I see you have a lot of money. Based on that, I suspect that you are a drug dealer.”
Possibly. But more likely: “I see you have a lot of money. Based on that, I want some of it.”