How much is a .999 fine silver coin worth?

Could you please elaborate on the value of a .999 fine silver coin? I'm particularly interested in understanding the factors that contribute to its worth. Does the coin's age, rarity, or minting location play a significant role? Additionally, how does the current market price of silver impact the overall value of such a coin? Is there a standard formula or methodology used to determine its worth, or does it vary depending on the individual collector or dealer? Your insights would be greatly appreciated in helping me gain a better understanding of the valuation process for this specific type of silver coin.