Fred Baumann stepped outside to look for the truck. It was nearing noon, which meant that collectors across the city would soon be heading to the Upper East Side on their lunch breaks.

It was the first day of baseball card season, and Mr. Baumann, one of the owners of Alex’s MVP Cards and Comics, still remembers the time a shipment was accidentally delivered to a nearby restaurant and sat undiscovered for a week, provoking a near meltdown for a small group of adult men.

Running one of the last sports-card stores in the city means constantly disappointing people. Most often it’s the guys who think the baseball cards collecting dust in their closets might be worth big money. Mr. Baumann gently deflates the expectations of about 20 would-be sellers every day, having to tell them that only about four cards from their childhoods are worth anything now.

“People think if it’s old, then it must be worth money,” Mr. Baumann said. “I try to explain it to them, but they just don’t stop talking. That’s the painful part.”