Serious collectors want all of their coins to be authenticated and graded by a third party that has certified their value, McCartney says.Ĭoins are typically graded on a scale of one to 70. You should also send your coin to a rare coin authentication and grading company, such as Numismatic Guaranty Company or Professional Coin Grading Service, to be independently evaluated. 'In general, the internet has a lot of misinformation about coin prices,' he says. If you're lucky enough to find this rare penny or have another coin you think may be valuable, start by contacting a reputable coin dealer or auction firm rather than relying solely on information found on Google, McCartney says.
