Brennan Hess, the manager at NashCards, said the theft happened last Monday after the man asked to see several high-value items.
Video shows man running from store after allegedly stealing Pokemon cards in Montgomery County
Hess said the man requested to look at two individual cards, each worth more than $2,500, as well as a sealed booster box valued at $4,200.
While employees were nearby, the man suddenly grabbed the items and ran from the store to a waiting vehicle, Hess said.
"Employees were right there. He just took them and ran, just gone in the parking lot," Hess said.
Police said the suspect fled in seconds, making off with the high-end collectibles worth thousands of dollars.
"The ones that were taken, multiple thousands of dollars. Collectively about $10,000 worth of stuff in just three items, so it does add up quickly," Hess said.
The theft is part of a broader trend of Pokémon cards being targeted for their high resale value, Hess said.
Stores in New York and Boston have also been hit in recent months, including a January smash-and-grab robbery in New York in which armed men made off with Pokémon cards worth about $100,000.
"It's certainly becoming a target, such as like a jewelry store or a pawn shop," Hess said.
NashCards did recover one of the stolen cards after police determined it had been sold to a store in Bensalem.
That store is now out of the money it paid for the card, according to the report.
Hess said the incident has prompted the shop to increase security measures.
"It's definitely something you gotta take into account going forward for sure," he said.
Police have not identified a suspect. They said the man got away in an older model tan SUV.