They say that freedom isn't free. They also say that it's priceless. But Sotheby's came up with a workable figure this week. $21.3 million.A copy of the Magna Carta sold at auction for that price (complete with seal of King Edward I who stamped it in 1297 - though King John originally agreed to the basic declaration of human rights in 1215). Apparently the auction house expected to fetch $30 million, but either freedom isn't in demand these days, or collectors decided to wait on one of the 16 other copies. Perhaps the oddest note is that this copy belonged not to a museum or even a Brit, but to Texas billionaire Ross Perot. He had parked it at the National Archives in Washington, where it was on display next to the Declaration of Independence and Constitution.There's no telling what those signed originals would go for on eBay or if the Bush Administration might want to find out while they still have value.The Magna Carta copy was purchased by the Carlyle Group, a private equity firm that counted former President George H.W. Bush as a shareholder and advisor until at least 2003 and 2004 respectively. There's no word on how much they expect the item to appreciate in value, or where it will be kept.