Pennies with visible mintmarks are cheapest. "Ghost" (barely visible) mintmarks can fetch some money. The plain of the coin version is the most valuable, and the penny with a strong reverse is the ...
Now, your grandad's dreams of getting a lottery-sized prize from his coin collection just might come true if you can find any of the most ... more valuable than their regular fancy Proof siblings.
What looks like a normal UK 20p turned out to be an experimental coin that never made it into circulation. It's valued at ...