The £102 million mostly relates to the renovation of Buckingham Palace. If they were under State control, we'd still pay these costs and honestly, when was the last time a State led project came in under budget?
Anyway, let's look at the ownership of the Crown Estates. From what I can see, if the Government abolish the Monarchy, the ownership of the CE reverts to the Sovereign unless there is some form of agreement reached during the abolition process.
It doesn't appear quite as simple as no Queen, everything becomes State owned.
If I were the Queen, should they go for abolition, I'd be doing a very careful cost analysis of the financials of the various palaces/castles and offer the money pits to the State, whilst keeping the ""good" assets. Politicians would crow that they've got a good deal in securing Buck Palace or what have you then the taxpayer would be lumbered with the entire costs going forward.
There's also the current financial arrangements of the Crown Estates where ALL the profits are handed to the Treasury and a sum of around 25% is handed back.
Do you honestly think the Windsor's are going to be paying 75% tax going forward? Really?
My gut feeling is that abolition would cost a hell of a lot more going forward and that where we've got the Queen now, politicians would soon take up residence. Because you know they're so worth it.