So the Irish presidency is 2½ times cheaper funded by a population 13 times smaller. So it actually costs more per head of population.
Say the Irish presidency cost £1m. And Ireland has a population 5m. Each person pays 20p.
At costing 2½ more the RF would cost £2.5m. The UK has a population of 67m. That's less than 4p a person.
So it would seem like the RF is a bargain.
We don't pay any wages to the RF. The king pays those out of his own money. They pay for the upkeep of their own homes. And as for Buck Palace, Clarence House, St James,Palace, etc, they'd still be paid for by the public. They're working govt offices. They won't just disappear.
Only the king and William, plus their wives and children get protection. That's not much more than a president would get for their family. For the rest of the family, protection is only provided if a family is on an official engagement.
Talking about voting. A national election costs over £100m. (About £110, I think.) So if a president seves a 5year term, the election alone costs £20m a year.
So it's clear from the figures you're giving me that the RFv is cheaper than your choice of president, ie Ireland's. Therefore I guess you're more concerned with democracy.
We don't seem to be great at choosing leaders in the UK. However, we have multiple tiers of democratically elected politicians in the UK. Parish councils, borough councils, county councils, mayor's, devolved govts, national govts. And still people constantly moan over who is chosen. And it's divisive because one side always gets someone they didn't choose. There are many advantages to having monarchs who build up knowledge and worldwide contacts over many years. Monarchies have proved to provide stable forms of goals in prosperous countries.
I know I won't persuade you to change your mind but it really isn't as simplistic as Republic! would have you think.