How much will constructing a plant that creates fusion power cost?

The next step for fusion research is the construction of the ITER, a large international fusion experiment in the south of France, ITER will test the materials, engineering and science which will enable the first commercial fusion plants to be built. The first of these is expected to cost in the region of £10 billion – roughly the cost of ITER – but, of course, it is expected that the construction cost will diminish as more and more are built.