From John Jencek's vcoins.com store. http://www.ancient-coins.com/

                        F215: MYSIA Cyzicus. Britannicus, Antonia & Octavia. 
                        Children of Cladius. RARE. (see STORY)   US$ 1,500 
                                € 1.102,85
                                £ 748,33
                                SFr. 1.812,17

                              Rates for 4/20/2007



                        Stock No. F215 

                        F215: MYSIA Cyzicus. Britannicus, Antonia & Octavia. 
                        Children of Cladius A.D. 41-54.: AE 12 (1.67 g). Head of 
                        Britannicus right. / Busts of his sisters. RPC 2248. 
                        Extremely rare. F/VF Ex Donovan coll.
                        The legend “New (or young) Germanicus” for Britannicus 
                        on the obverse dates this coin to before AD 43. The 
                        three children of the emperor Claudius represented on 
                        this coin were all fated to die at the hands of their 
                        adopted brother Nero. The youngest child Britannicus 
                        died by poison in AD 55 after nearly a decade of his 
                        stepmother (and cousin) Agrippina II dominating the 
                        imperial court for the ascension of her son Nero at the 
                        death of Claudius. Octavia, the middle child, was 
                        married to Nero in AD 53 but was divorced, banished, 
                        then horribly executed in AD 62 after Nero fell in love 
                        with the jealous Poppaea Sabina. Antonia, the oldest 
                        child, was married twice to highly influential men, the 
                        first of whom was put to death by Claudius, the second 
                        by Nero. She was a dangerous threat to the heirless Nero 
                        as the closest surviving member of the family and so was 
                        put to death after her refusal to marry him in AD 66.