America’s most valuable postage stamp sold for nearly $4.4 million on Friday. The 1868 one-cent "Z" Grill was sold as part of the collection owned by "Bond King" Bill Gross, who co-founded asset ...

Why have prices for very rare stamps risen so high ... an American collector, who outbid King George V of England, setting its first world-record price of $35,000. Its most recent sale, to ...