It certainly has the potential to be. Remember most of the costs related to fission are safety measures, plant decommissioning, and waste disposal. If we merely had to operate the reactor without concern for those issues, fission would be incredibly cheap. The fuel costs and basic technical requirements to operate a reactor are trivial in comparison.

Fusion produced 4x more energy per mass of fuel compared to fission, isn’t at risk of meltdown, and has the potential to produce negligible radioactive byproducts. In addition, it outputs helium which is an important and finite strategic resource.

Even if the cost of fuel goes up dramatically compared to uranium reactors, it might still outperform nuclear in a big way. However, sourcing He-3 from the moon might be a lot cheaper than you think. My day job is related to space resource utilization. Transporting resources off the surface of the moon could be quite economical once we reach a sufficient level of development.