Re: Future of the Monarchy
There's a fairly good (not recent) article here :
https://www.independent.co.uk/news/b...-a8345436.html
You can't get a breakdown of the 345m because it's just an estimate the main dispute seems to be who owns the Duchy of Lancaster/Duchy of Cornwall income and Prince Charles's entitlement. I've no idea of the history of that.
In terms of security you'd have to compare this with other public figures such as the PM etc, House of Commons, House of Lord etc. all the protests. Previous prime ministers also receive security as well the cost of Downing Street Chequers refurb of the Downing street briefings room, the refurbishment of the houses of Parliament and big ben. All that comes from the public purse.
https://www.republic.org.uk/the_true_cost_of_the_royals