The value of euro coins issued in two of the smallest European states - the Vatican and Monaco- has vastly increased since the death of Pope John Paul II and Prince Rainier of Monaco.
A two-euro Vatican coin is currently worth 160 euro on the European coin-collecting market. The price for the set of all eight euro coins, minted in 2004, exceeds 500 euro, according to The Independent.
A one-euro Monaco coin can be worth up to 60 euro.
Both types of coins, plus the ones minted in San Marino, have been collectors' favourites since 2001. But interest in them has grown even more, since the leaders of the Vatican and of the Principality of Monaco passed away.
Their deaths were followed by speculation that new coins, carrying the heads of the new Pope and Prince Albert II (the new monarch of Monaco), may be issued, provoking the rush over the current coins.
The Vatican, Monaco and San Marino have permission by the European Commission and the European Central Bank to mint a certain number of "souvenir" euro carrying their national symbols.
The Vatican, for instance, is allowed to mint one million euro coins a year, or 1.3 million in the year of a papal death, writes The Independent.
Although initially issued to circulate like "normal" coins, the euro of these micro-states have been literally grabbed by collectors and coin dealers.
This has turned out to be so lucrative that Andorra, another European micro-state, has recently shown interest in minting its own coins and has asked Brussels' permission to do so.