What this coin looks like (obverse, reverse, mint mark location, special features, etc.):
One major variety of the 1806 Draped Bust Half Dollar features a 6 Over Inverted 6 overdate. The "6" was initially punched upside down and was later corrected. This resulted in a "6" being struck over an upside-down "6" on the coin. It is very easy to spot this variety as there is a large "spike" extending from the right side of the "6" (the spike being the upper part of the "6" being inverted). This feature is depicted by the arrow in the example image of the coin above.
Coin valuation chart: Typical coin prices, values and worth per grade or condition - in USD