The world of collectibles has changed. There was a time when the only place to trade collectibles was with a stack of dog-eared cards in the corner of the schoolyard. That was fun until you left school. eBay created a market that was always open and now covers everything from baseball cards to works of art. It’s a place where sellers can always find buyers, buyers can always find sellers, and everyone can find current prices. But even eBay still requires shipping goods, and buyers still need to hope that a rare item on offer is as genuine as …