You should also consider that the whole idea of a network of large independent system operators is part of the reason why power can be cheap in the US - you can

You should also consider that the whole idea of a network of large independent system operators is part of the reason why power can be cheap in the US - you can dispatch the most economically viable generation source over a wide area. The UK is roughly equivalent to a mid-sized US state in terms of energy market (roughly half the market of California, for example). Having the UK act as it's own electrical balancing authority and responsible for it's own power contracts is remarkably inefficient. The prices reflect that. In a sane world all of Europe would be under a common balancing authority that could dispatch power economically based on the generation and load across the entire region. The US is moving in this direction, we've already got several very large BAs and will eventually be under a single authority or a few very large regional authorities. This is one of those many cases where the politics of the situation and the physics of the situation go to war and the politics wins.