The combination of "copper" and "penny" might not seem like the best formula for valuable coins considering that you can find ...

But he’s not forgetting small change ... metal rollers at funfairs. New copper pennies vanished from circulation in 1982—73 years after the first Lincoln penny was minted.

The combination of “copper ... Penny-Doubled Die Obverse Here is another coin valued at $126,500 (at least, in MS-64 condition) — and most of that value is due to doubling on the date ...