What country if you don't mind me asking? Did the package appear tampered with, as though it had been opened and re-packaged? Would be nice to know which countries charged VAT vs which ones they slipped through on. I listed them as commercial engraving samples, which usually find their way through customs without any issues with the 1oz coins, but perhaps 5oz was a bit heavy for that...
The Dutch customs are very random when it comes to checking packages. The allowed import value over here is around 21 euro and they randomly select packages and see if it follows the rules. If not, you gotta pay up. For example; I've had three medium/high-range phones delivered from China without a problem, but I've had to pay VAT for a 25 euro watch.