Greece's economic troubles have the world's attention, but Greek currency from another era is taking the spotlight this week in New York.

A collection of more than 600 ancient Greek coins is expected to fetch millions of dollars when they are put up for auction Wednesday. British coin expert Paul Hill says collectors consider ancient Greek coins to be some of the finest and most artistic money ever produced.

The coins depict such iconic ancient Greek images as gods, minotaurs, and Alexander the Great in battle. The rarest coin in the collection, engraved with pictures of a satyr and a griffin, is about 6,000 years old and is estimated to be worth $650,000.

The collection was gathered from across the ancient Greek empire, which included parts of modern-day Libya and Pakistan.

Hill says many people are investing in are coins as an alternative to shaky banks and the volatile global stock market.

PAUL HILL, ANCIENT COIN SPECIALIST, NOBLE INVESTMENTS: “Ancient Greek coins are considered to be the very finest artistic coins that have ever been produced and it is full of wonderful rarities, this collection and it really covers the whole Greek world from Italy and Sicily in the West through to mainland Greece, the coast of Turkey and Asia minor and the coast of North Africa too, so it's got a huge scope in the collection. And they're wonderful types on the coins, wonderful images of gods and goddesses, of mortal heroes, of mythological beings, the minotaur, lots of myths and legends, so there's artistic beauty and great historical significance as well to this collection.''

HILL: “The coin that's on the front cover of our catalogue is a gold stater from a city called Pantikapaion, which is on the coast of the Black Sea and it has an image of a satyr, which is a mythological being and it's the facing head of the satyr of the coin and I think just artistically, it's

such an incredible coin. It's considered one of the masterpieces of the ancient Greek series and that's the top lot in our sale. It has a pre-sale estimate of $650,000 and we hope that on Wednesday evening, it will get to over a million. We're confident it will. That would be great if it does.''

HILL: “So yes, another coin we have in the collection's very exciting historically. It's a coin of Alexander the Great. It's a silver dekadrachm piece and it was actually struck at the time of Alexander's campaign in the far east of his empire in India and the actual front side of the coin

depicts Alexander the Great on horseback pursuing an Indian elephant with the Indian King sitting on top of it, so it's a really important and historical coin, which actually depicts events happening at the time it was struck in the 320s B.C.''

HILL: `Two types of people really, who I think are going to be buyers at this sale. They'll be first of all, the collectors, who really appreciate these coins for their historical significance in their artistic beauty and they'll be here supporting the sale very strongly, but then I think they're also now people investing in coins because, you know, they see them as a very good alternative to banks and the stock market. Coins are very portable, good good things to put your money into and I think in the last few years, yeah, there has been an upward trend in the markets, certainly in the last couple of years, so there are people looking at them as quite a good mid to long-term investment.''