The Busan Station Store is in the 2F waiting hall (206 Jungang-daero), open 08:30-22:00. The nearby Busan Station Branch opens at 11:00 and the Daiso at the station at 10:00. We couldn't check stock at each Busan store, so ask the staff. The Carrot Carotene Relief Cream 70ml+30ml is an Olive Young exclusive, and 70ml is fine in carry-on.