If this pans out fusion energy would be completely viable with enough investment. Right now tokamaks don't really have a pathway to being commercially viable and are basically 40 years away. For starters, If you can cut the cost by 2-4x you are right in the ballpark of what you would need to build a working tokamak fusion power plant. You would need to do better than that for fusion to be a viable power source but tokamak fusion was always only a magnitude away unlike other hypothetical fusion energy alternatives.