The British Museum has eventually agreed a price for the purchase of a rare Anglo Saxon coin. The coin was originally sold to a private purchaser outside the UK, but the government placed a temporary export ban on it , claiming that it was important to keep such national treasures within the country because they are so closely connected to the country. This article in the New York Times questions whether this forced retention of British artefacts conflicts with our reluctance to return artefacts to other countries, even though those pieces hold a national importance to their original owners.
New York Times 
Museum Buying Rare Coin to Keep It in Britain
By MATTHEW HEALEY
Published: February 8, 2006
A rare 1,200-year-old Anglo-Saxon gold coin that was sold at auction to an American collector will not be leaving Britain after all.
The British government blocked the export of the coin last year, and the British Museum has raised the funds needed — more than $650,000 — to buy it back. The acquisition is to be announced today.
A treasure hunter discovered the coin in 2001 in Biggleswade, on the banks of the river Ivel about 60 miles north of London, using a metal detector. The gold penny, called a mancus, weighs about an eighth of an ounce and is slightly larger than an American penny.
The coin is highly desirable, according to numismatic experts. Besides being in remarkably good condition, it bears an exquisite portrait of Coenwulf, King of Mercia (796-821), the only depiction of him known on a gold coin. The reverse has a design inscribed “De Vico Lvndoniae,” identifying the Anglo-Saxon settlement, now London, where it was minted. The coin’s sale in October 2004 set a record price for a British coin. The buyer was Allan Davisson, a collector and dealer from Cold Spring, Minn. He paid a little over $400,000 at the time.
But Mr. Davisson was blocked from bringing his prize home. David Lammy, the British minister responsible for protecting cultural heritage, announced in August 2005 that based on the historic and artistic importance of the coin, he would give the British Museum time to raise extra funds to buy it back. The deadline was Feb. 2.
The British Museum was able to tap sources that included the National Heritage Memorial Fund, which is supported by lottery income, and is “very happy” with the outcome, according to Hannah Boulton, a museum spokeswoman.
The tug of war over this coin illustrates the workings of British law on antiquities. Considered more liberal than other countries, Britain allows those who find buried treasure to receive fair market value for it.
Mr. Davisson conceded in an interview in January, “I definitely thought this coin was worth more than I paid for it.”
Although the British Museum did bid in the auction, its limited funds forced it to drop out. Mr. Davisson later resold the coin to an American collector for $650,000. The British government accepted the new, higher figure as the bona fide value that should be paid for the coin.
Ms. Boulton said there was no paradox in that Britain, which has refused to return famous antiquities like the Rosetta Stone to Egypt, is trying to block export of an item like the coin. “It’s not a comparable situation,” she said. “These items are all part of a wider world collection. Visitors to the British Museum can compare and contrast cultures from all civilizations — that is a concept worth defending.”
Mr. Davisson confessed to having mixed feelings. “Emotionally, I wish I could bring the coin here, but intellectually, I know it belongs in the British Museum.”