The most expensive items ever auctioned

Placards don't usually incite a bidding-war among collectors, but this particular one, called Bed Peace, sold at Christie's for $154,628.

It was created by John Lennon during the Montreal Bed-In for Peace, a pacifist event he held with his wife Yoko Ono at the height of the Vietnam war in 1969.

Related: John Lennon guitar expected to fetch $800,000

Lennon and Ono spent a week in bed in their nightclothes, sitting up to convey the message of peace to a group of journalists and politicians.