The price difference appears to be the watchband and accessories bundled with the watch.

FORBES: Magazine Article

Josh grew increasingly befuddled, as Robbins continued to make the coin vanish and reappear on his shoulder, in his pocket, under his watchband.

NEWYORKER: A Pickpocket��s Tale

As the Christie's catalog chastely describes it, the panel depicts "a man and woman amorously panning for gold, " animated by a button in the watchband.

FORBES