I'll go way back and point out the 1797 Draped Bust dollar (skinny eagle). About 7,000 were minted. It's rarity is not reflected in its price compared to its brothers and sisters of much higher mintage. In this case, I believe it is due to demand. Most people just want one example of this type. Not many attempt a set. So, my theory is that there is no demand for a specific date. The demand is primarily for the type.