They also outsourced a ton to make CG cut-scenes and such, which can rack up a bill very quickly. ProbablyMonsters was an incubator, not a parent company, as I understand it. I too am skeptical of there only being one source in Colin Moriarty, but I trust Jordan Middler to vet the story, even if he isn’t corroborating it, and as others have mentioned, the credits are literally over an hour long, which is evidence that supports the high costs.