It's worth one cent. The phot gets blurry when I enlarge but it looks like a plating blister which is very common. Definitely not a mint error. Welcome to CT.
It's hard to tell from the pictures, but from what I can see it appears to just be a plating blister or maybe a die chip.
To determine the value, you need to know the condition. To determine the condition, you need to determine the grade. You need to see both sides of the coin to determine the grade, that is, unless you only want to pay half what it is worth. ~ Chris
