Eucratides I, sometimes called Eucratides the Great, was one of the most important kings of the Greco-Bactrian Kingdom, which was centered around the northern part of present-day Afghanistan. Eucratides has prestigious coinage, suggesting a rule of considerable importance. This page covers silver tetradrachms that look like our pictures. Weigh is about 16 grams, plus or minus 1 gram.
The coin in our main picture comes from Baldwin's in London where is sold for $1200 USD during a 2006 auction. It would probably sell for more today.
worn: $300 US dollars approximate catalog value
average circulated: $1000
well preserved: $3500
As always, coins like this stand on their own merits and catalog values are very rough (almost meaningless) guides. To give a better idea of value, consider the images to the right, labeled (A) through (D).
The (A) coin is a superb specimen, sold by Roma Numismatics for $2500
The (B) coin appears more rough and worn. It is an $800 coin, or so.
Coin (C) displays porous, marred surfaces and hardly any detail. It would probably sell for $250 to a collector of ancient coins.
(D) is an obvious fake, worth zero.