The £1.25 comes from the amount of the Sovereign grant divided by the number of people in the country. That amount is currently about £70 million pounds.
It includes money for the upkeep and renovation of Buckingham Palace, which is not owned by the person of Monarch directly, but which is held be her/him because they are Monarch. So in the event that a Monarch is replaced by and elected Head of State, the ex-monarch would have to give up any claim to Buckingham Palace because they don't actually own it. (They could move to Sandringham, or Balmoral, or one of their other many homes.)
So, the new HoS could live in Buckingham Palace if we thought that was a good idea, and so we wouldn't need a new "Palace or two". And the "firm" that Callistemon says is keeping the whole shebang on the road will now be keeping the new shebang on the road. HM and Family will have to employ their own shoe-breaker-in'ers.
Not sure who owns the limos for sparkly hats, but I suspect its not the personal property of HM.
So, your kitchen table economics needs a bit of looking at Callistemon. Not really so brilliant after all.
Should we pay kids to go to school?
Reform UK’s Richard Tice allegedly failed to pay £100,000 in corporation tax



