Re: It won't cost that much
"Since it only has to provide location information within Great Britain + Gibraltar*"
Which would be correct if any of these systems were actually built so us plebs could drive around without having a sense of direction. Of course they aren't built for that, they are built so our armed forces can drop bombs on the 'right' things without the need for someone to sit in sight of it pointing a laser at the target.
Building a system that only covers the UK would only be of use if we have a civil war, which hopefully won't be the way Scotland becomes independent.