A 5-cent stamp from 1875 sold for $525,000 at a Sept. 24 auction conducted by Robert A. Siegel Auction Galleries. The auction catalog had estimated that the stamp, which has not appeared on the market ...

Stamp collecting has been a popular hobby since the 1840s. Because of this, you'll find stacks of stamps in stellar condition at estate sales, in thrift shops, through online marketplaces, and ...