Hello and welcome.

We don't have too many folks from Greece as active members here on the forum. Being a coin collector in Greece can be challenging. The Greek government encourages folks to be collectors of modern Greek coins (defined as anything made after the founding of the first Greek Republic in 1830), which results in rather high prices for 19th century Greek coins due to strong local demand.
For coins older than 1830, however, it's a different story. These are considered cultural artifacts and are Property of the State. You cannot "own ancient coins" in Greece; you certainly cannot buy, sell or export them. You can buy or sell the
right to be the custodian of an ancient coin, which looks similar to outright ownership but includes some important restrictions, such as a duty of care to protect the coin, the requirement for the coin's location to be registered with the government, and for the coin to be available to be produced for examination on demand by a recognized archaeological authority.
Most folks simply find the rules and regulations too burdensome, and don't even try to collect or take an interest in pre-1830 coins. This does have the unfortunate side effect that very few experts in ancient and mediaeval Greek coinage actually reside in Greece.
Don't say "infinitely" when you mean "very"; otherwise, you'll have no word left when you want to talk about something really infinite. - C. S. Lewis