Prototypes and early models are extremely expensive but there are encouraging signs that fusion plants could be cheaper. The technology is inherently safer so site-preparation would be cheaper (can be a massive bill for fission), the same consideration could lead to factory-style production of magnets and other similar components, more interest from the public (safe, climate-friendly) and any sea-touching countries (energy-security) would mean more demand pushing economies of scale further, safer means less time passing certification, etc.