That would depend on the country of the coinage.
500
HALF a dollar - $0.50
It's worth 50 cents.
No such coin exists
The British currency has never included cents.
The 1915 Eagle is a common Philadelphia Mint issue coin and assuming it's circulated and in collectible condition average values are $800.00-$925.00.
The Bicentennial Half Dollar is worth from $2-5
Unless the coin has an "S" mintmark, such a coin is only worth $.50 because it is extremely common.
The coin is still in circulation and is face value.
If the coin has any wear the value is for the silver about $12.00
The coin is still in circulation today and has face value only.
$9 to $35,000 depending upon the mint mark and the condition of the coin.