The article claims that the whole project only cost $40,000, and then compares that to electric conversion offerings that cost $75,000 (and mentions that the global conversion market in 2024 was $5.9 billion). I think the implication is that there could be a large market for FSD conversions that goes beyond passion projects because it is not only possible but affordable.

I would be surprised however if this project only cost $40,000, when you factor in the cost of labor and maintaining a facility to do this work.