Pontius, you are still thinking in old fashioned terms.
The costs incurred by an overseas presence, like the UK currently has, do not need to be part of the Democratic Peoples Republic of Jockistan.
Remember all the people who said we couldn't not have a new MPA, or Harriers or Soldiers in Germany or Aircraft Carriers?
New Caledonia (2016) Ltd will manage fine by running the country like a business, not like a football club where you spend the money and then wonder where it will come from.
Whatever else he is, Wee Eck is not daft. Scotland has no need for Trident, but that's not to say that the way of doing things would rule out allowing the RN to keep it in Scotland, at a price of course. Can you really see England not using Trident to stop something in ten years from now that they would use it to stop today?
Trident is a deterrent, but it will deter anyone from attacking Scotland whether it is ours or not. We are (physically) too close to England for Westminster to ignore a threat to us.
I don't see them ever using it, so why keep paying for it?