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However the Obamas decide to proceed, they’ll have to follow a few basic rules. For starters, they will have to pay for their own movers. And while Congress budgets $100,000 in household transition costs for every new administration, if the Obamas spend more than that — and most first families do — they will have to cover the expense of decorating their private quarters with private donations. In addition, they can’t change the public rooms without the approval of a committee of preservationists.
DECORATING the White House is the first lady’s job; she presides over the Committee for the Preservation of the White House, a board of appointees that includes her decorator and the White House curator, as well as art historians, furniture and decorative art experts and other advisers on historic preservation.
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Renovations of the public rooms, additions to the formidable collections of art and furniture, and any restoration work is overseen by the committee and financed by the White House Endowment fund, which now has assets of about $27 million.
http://www.nytimes.com/2008/12/18/garden/18whitehouse.html$100,000 (for a 4 or 8 year time period is a drop in the bucket)
EDITED TO ADDThe Obama's paid for the private residence renovations themselves WITH THEIR OWN MONEY when they moved in.
http://www.hiptics.com/2009/03/30/barack-michelle-obama-pay-for-white-house-renovations-with-their-own-money/