7. Sarcophagus of Menkaure
If it’s not obvious at this point, the British don’t really have a good track record of safely transporting cargo overseas. After this sarcophagus was found, the British assumed it’d look nice in their very own museum instead of leaving it in Malta, where it was found. The ship carrying it caught some bad weather and capsized. The sarcophagus was never found again. If you want to know what the value of this item is, you’d be better off asking an Egyptian historian what value he’d put on a sarcophagus of the pharaoh of the 4th dynasty, who built the third great pyramid of Giza. It’s probably priceless.