Because he's worth it.

"President Obama stayed only one night in Australia for the G-20 summit, but the entire presidential delegation required over 4,000 rooms costing in excess of $1.7 million for the entire stay. Rooms at three different hotels were reserved for the U.S. delegation, and due to the large number of countries involved in the summit, the Australian government parceled out available hotels to each nation's delegation. The majority of the U.S. delegation stayed at the Brisbane Marriott, with the remainder staying at two other Brisbane hotels, the Urban and the Adina...

While the average room cost in the three contracts came to $423/night, the U.K. Daily Mail reported the president's suite for his one-night stay on Saturday lists at over $2,000 per night. The Mail also reported on the extensive preparations to the president's room and the entire floor of the hotel to secure the area for his stay, which included a complete strip-down of the president's suite."

http://www.weeklystandard.com/blogs/obam...17m_820753.html