[Drago]

I definitely agree that it's not an unusual behavior. Some hamsters like large spaces straight away, while others may require a smaller but more manageable one to settle into. I'd say you'd be okay leaving him in the cage he's in if he's comfortable in it. He'll let you know when he's ready for a larger cage. Once he seems very confident or seems restless in the cage he has, then it would be time to add more space, bit by bit