Murray is a fourth-generation antique collector. His family immigrated to the Americas during the Irish Potato Famine and put aside every penny earned towards finding and buying Celtic collectables. Murray was on a trip to Cape Breton last summer when he wandered into an antique store and saw a rare Celtic stein on the shelf next to a bunch of other less notable ceramic wares. The only person in the store was a teenage summer clerk who looked like he would prefer to be hiking the Cabot Trail that sunny afternoon. Murray picked up the stein and examined it, barely able to contain his excitement at the find. The clerk looked up lazily at Murray and said, "five dollars" and promptly went back to his magazine. Murray's hand was shaky as he paid the clerk and hurried out of the store. A few weeks later, Murray put the stein on an online auction site and sold it to collector in Colorado for $3.3 million.

Do you think there was a valid contract between Murray and the store? Does the store owner have any claim to part of Murray's new fortune? Is there any possibility that the Colorado collector would not be able to keep the stein?

Please provide references.