According to British Coin Price Guide, as of September 2014, a "fine" 1825 George IV penny is worth approximately $450, while a coin minted in 1827 is worth $3370. The King George IV penny was minted between 1825 and 1827, as the smallest coin denomination available in the United Kingdom.
The value of a King George IV penny is determined by its condition and the year it was minted. A coin can be in poor condition, which is to have signs of wear all over it. These coins usually have no value. A coin is considered "fine," if it is considerably worn but some detail can still be seen. A coin which has only been in circulation for a few years is considered "very fine." "Extremely fine" means that the coin has not been in circulation very much and has practically no scratches. A coin can also not have been in circulation at all, in which case, it is referred to as "uncirculated."