A giant sale of 20,000 treasures from the house of Hanover, one of Germany's most illustrious royal families, has exceeded all expectations by raising more than 25 million euros ($30.1 million) at its halfway point, the organizers said. The sale had been conservatively expected to raise 12 million euros to help the sons of the controversial Prince Ernst August, husband of Monaco's Princess Caroline, maintain the family's neo-Gothic Marienburg castle near Hanover. But with just four of the 10 sales days completed, auctioneers Sotheby's announced that receipts already totaled 25.7 million euros. Buyers have been paying up to six times over the asking price for the most highly coveted items. A posthumous marble bust of Louise, Queen of Prussia, dating from 1823 sold on Saturday for 205,000 euros, after bidding started at between 30,000 and 50,000 euros. After a rest day on Sunday, the sale resumed on Monday. Ernst August, who has hit the headlines in recent years for fist fights with the paparazzi, is a descendant of the last German emperor, William II.