I suggest it be ditched now before it is usurped by the POTUS next month.

https://www.cbsnews.com/news/trump-u...i-theresa-may/

That's just one existential cost to the public. There are many more such as this, https://www.theguardian.com/uk-news/...m-palace-works.

The only benefit I can see for the general public is tourism. Is it worth the cost?

I have not so far found a number that includes security costs.