What this coin looks like (obverse, reverse, mint mark location, special features, etc.): One major variety is the 1806/5 Draped Bust Half Dollar featuring a "6" over "5" overdate. An 1806 date is struck over an 1805 date - which resulted in parts of the underlying "5" being visible within the "6". In addition - Parts of the "0" is doubled as portions of an underlying "0" can be seen within the number - and also a small part of the doubled "8" can sometimes be seen towards the bottom-right of the number. These features are depicted by the arrows in the example image of the coin above.
Coin valuation chart: Typical coin prices, values and worth per grade or condition - in USD