They should be able to keep it because they would be found by government workers so at least they should give the finder quarter of the treasure, Because the government might need the money to support the country’s needs
I hope i have been able to convince and not to confuse you that government should keep at least 70% of the treasure found
If you find gold or oil or something valuable the government will come and snatch it away. It is wrong and very dubious but that is the way they work. Even finding gold or buried or sunken treasure and the government will want their cut.
It is what they do and you cn be assured that whatever you have left will be taxed until you have nothing left.