How sure are you that the 'gold' and 'silver' you buy is really real?
Ever try to sell a $200 gold ring at a jewellry store before? They only wanna pay you a tiny fraction of what it's worth. I imagine the same thing would happen with a gold coin when you wanna cash in (if it's really real).
Believe it or not, lobster and crabs are crustaceans and are a part of the arthropod family, which include caterpillars, cockroaches, and spiders!