A penny dated 19D3 from the Denver Mint is likely a misprint or error, as the Denver Mint did not produce any coins in 1933 due to the Great Depression. If such a coin were to exist, it would likely be considered a valuable collector's item due to its rarity and historical significance. The value of the penny would depend on its condition, rarity, and demand among collectors, but it could potentially be worth hundreds or even thousands of dollars.