Is this his version of a slimmed down Monarchy? He has always been known to be a spendthrift with himself and very careful with everyone else. So his residences are:
Buckingham Palace, Clarence House, Sandringham, Windsor Castle that is currently being renovated for him, Highgrove, Balmoral, Birkhall and Castle of Mey, plus his Romanian home and Llwynywermod in Wales.